diff --git a/.gitignore b/.gitignore
index 31f5f1e..c456446 100644
--- a/.gitignore
+++ b/.gitignore
@@ -24,3 +24,4 @@ hs_err_pid*
 
 # editor files
 .vscode
+.*.swp
diff --git a/README.md b/README.md
index a915e84..0178939 100644
--- a/README.md
+++ b/README.md
@@ -1,2 +1,5 @@
 # 数据结构和算法之美
-# 请点击查看：[https://time.geekbang.org/column/intro/126](https://time.geekbang.org/column/intro/126)
+# [https://time.geekbang.org/column/intro/126](https://time.geekbang.org/column/intro/126)
+
+# Java rate limiting library/framework
+# https://github.com/wangzheng0822/ratelimiter4j
diff --git a/c-cpp/05_array/Array_gp.c b/c-cpp/05_array/Array_gp.c
new file mode 100644
index 0000000..0147a12
--- /dev/null
+++ b/c-cpp/05_array/Array_gp.c
@@ -0,0 +1,278 @@
+#include "Array.h"
+
+#include <string.h>
+#include <stdbool.h>
+
+Array* arrayCreate()
+{
+    struct Array *array = NULL;
+    array = malloc(sizeof(*array));
+    if (NULL == array)
+    {
+        return NULL;
+    }
+
+    array->p = NULL;
+
+    array->size = 0;
+    array->typeSize = 0;
+    array->len = 0;
+
+    array->dup = NULL;
+    array->free = NULL;
+    array->match = NULL;
+
+    return array;
+}
+
+void arrayInit(Array *array, int size, int typeSize)
+{
+    if (NULL == array
+        || typeSize <= 0
+        || size < 0)
+    {
+        return;
+    }
+
+    void *p = calloc(1, size* typeSize);
+    if (NULL == p)
+    {
+        return;
+    }
+
+    array->p = p;
+    array->len = 0;
+    array->size = size;
+    array->typeSize = typeSize;
+}
+
+int arrayInsert(Array *array, size_t pos, void *const value)
+{
+    if (NULL == array)
+    {
+        return -1;
+    }
+
+    if (array->len >= array->size)
+    {
+        return -2;
+    }
+
+    if (pos > array->size || pos <= 0)
+    {
+        return -3;
+    }
+
+    char *pBegin = array->p;
+    for (size_t i = array->len; i > pos - 1; --i)
+    {
+        void *pNew = pBegin + i * array->typeSize;
+        void *pOld = pBegin + (i - 1) *array->typeSize;
+        if (NULL != array->dup)
+        {
+            array->dup(pNew, pOld);
+        }
+        else
+        {
+            memcpy(pNew, pOld, array->typeSize);
+        }
+    }
+
+    void *pCopy = (void*)(pBegin + ((pos - 1) * array->typeSize));
+    if (NULL != array->dup)
+    {
+        array->dup(pCopy, value);
+    }
+    else
+    {
+        memcpy(pCopy, value, array->typeSize);
+    }
+    ++array->len;
+    return 0;
+}
+
+size_t arraySearchValue(Array *array, void* const value)
+{
+    if (NULL == array)
+    {
+        return -1;
+    }
+
+    char *pBegin = array->p;
+    size_t i = 0;
+    for (; i < array->len; ++i)
+    {
+        int nCmp = 0;
+        if (NULL != array->match)
+        {
+            nCmp = array->match(pBegin + i * array->typeSize, value);
+        }
+        else
+        {
+            nCmp = memcmp(pBegin + i * array->typeSize, value, array->typeSize);
+        }
+
+        if (nCmp == 0)
+        {
+            break;
+        }
+    }
+
+    return i;
+}
+
+void* arrayIndex(Array *array, size_t index)
+{
+    if (NULL == array)
+    {
+        return NULL;
+    }
+
+    if (index > array->len
+        || index <= 0)
+    {
+        return NULL;
+    }
+
+    char *pBegin = array->p;
+    return pBegin + array->typeSize * (index - 1);
+}
+
+int arrayModify(Array *array, size_t pos, void *const value)
+{
+    if (NULL == array)
+    {
+        return -1;
+    }
+    if (pos > array->len
+        || pos <= 0)
+    {
+        return -2;
+    }
+
+    char *pBegin = array->p;
+    void *pOld = pBegin + (pos - 1) * array->typeSize;
+    if (NULL != array->dup)
+    {
+        array->dup(pOld, value);
+    }
+    else
+    {
+        memcpy(pOld, value, array->typeSize);
+    }
+
+    return 0;
+}
+
+size_t arrayLen(Array *array)
+{
+    if (NULL == array)
+    {
+        return 0;
+    }
+
+    return array->len;
+}
+
+size_t arraySize(Array *array)
+{
+    if (NULL == array)
+    {
+        return 0;
+    }
+
+    return array->size;
+}
+
+void arrayEmpty(Array *array)
+{
+    if (NULL == array)
+    {
+        return;
+    }
+
+    free(array->p);
+    array->p = NULL;
+    free(array);
+    array = NULL;
+}
+
+void arrayDelValue(Array *array, void *value)
+{
+    if (NULL == array)
+    {
+        return;
+    }
+
+    char* pBegin = array->p;
+    bool bCopy = false;
+    for (size_t i = 0; i < array->len; ++i)
+    {
+        if (!bCopy)
+        {
+            int nCmp = 0;
+            if (NULL != array->match)
+            {
+                nCmp = array->match(pBegin + i * array->typeSize, value);
+            }
+            else
+            {
+                nCmp = memcmp(pBegin + i * array->typeSize, value, array->typeSize);
+            }
+
+            if (0 == nCmp)
+            {
+                bCopy = true;
+                continue;
+            }
+        }
+        else
+        {
+            void *pOld = pBegin + (i + 1) * array->typeSize;
+            void *pNew = pBegin + i * array->typeSize;
+            if (NULL != array->dup)
+            {
+                array->dup(pNew, pOld);
+            }
+            else
+            {
+                memcpy(pNew, pOld, array->typeSize);
+            }
+        }
+    }
+
+    if (bCopy)
+    {
+        --array->len;
+    }
+}
+
+void arrayDelIndex(Array *array, size_t pos)
+{
+    if (NULL == array)
+    {
+        return;
+    }
+
+    if (pos > array->len || pos <= 0)
+    {
+        return;
+    }
+
+    char* pBegin = array->p;
+    for (size_t i = pos - 1; i < array->len - 1; ++i)
+    {
+        void *pOld = pBegin + (i + 1) * array->typeSize;
+        void *pNew = pBegin + i * array->typeSize;
+        if (NULL != array->dup)
+        {
+            array->dup(pNew, pOld);
+        }
+        else
+        {
+            memcpy(pNew, pOld, array->typeSize);
+        }
+    }
+
+    --array->len;
+}
\ No newline at end of file
diff --git a/c-cpp/05_array/Array_gp.h b/c-cpp/05_array/Array_gp.h
new file mode 100644
index 0000000..662ef8a
--- /dev/null
+++ b/c-cpp/05_array/Array_gp.h
@@ -0,0 +1,48 @@
+#ifndef __ARRAY_H__
+#define __ARRAY_H__
+
+#include <stdio.h>
+#include <stdlib.h>
+
+typedef struct Array
+{
+    // pָ��Ŀռ��С
+    size_t size;
+    // pָ���Ѿ�ʹ�õĿռ��С
+    size_t len;
+    // �������͵Ĵ�С
+    size_t typeSize;
+    // ֵ���ƺ���
+    void(*dup)(void *ptr, void *key);
+    // ֵ�ͷź���
+    void(*free)(void *ptr);
+    // ֵ�ȽϺ���
+    int(*match)(void *ptr, void *key);
+    // ������ݵ�ָ��
+    void   *p;
+}Array;
+
+#define arraySetDupMethod(a, m) ((a)->dup = (m))
+#define arraySetFreeMethod(a, m) ((a)->free = (m))
+#define arraySetMatchMethod(a, m) ((a)->match = (m))
+
+#define arrayGetDupMethod(a) ((a)->dup)
+#define arrayGetFree(a) ((a)->free)
+#define arrayGetMatchMethod(a) ((a)->match)
+
+Array* arrayCreate();
+void arrayInit(Array *array, int size, int typeSize);
+
+int arrayInsert(Array *array, size_t pos, void *const value);
+size_t arraySearchValue(Array *array, void* const value);
+void* arrayIndex(Array *array, size_t index);
+int arrayModify(Array *array, size_t pos, void *const value);
+
+size_t arrayLen(Array *array);
+size_t arraySize(Array *array);
+
+void arrayEmpty(Array *array);
+void arrayDelValue(Array *array, void *value);
+void arrayDelIndex(Array *array, size_t pos);
+
+#endif // !__ARRAY_H__
\ No newline at end of file
diff --git a/c-cpp/06_linkedlist/Dlist/Dlist.c b/c-cpp/06_linkedlist/Dlist/Dlist.c
new file mode 100644
index 0000000..d41cb45
--- /dev/null
+++ b/c-cpp/06_linkedlist/Dlist/Dlist.c
@@ -0,0 +1,220 @@
+/*************************************************************************
+ > File Name: Dlist.c
+ > Author:  jinshaohui
+ > Mail:    jinshaohui789@163.com
+ > Time:    18-10-07
+ > Desc:    
+ ************************************************************************/
+#include<stdio.h>
+#include <stdbool.h>
+#include "./Dlist.h"
+
+
+
+void dlist_init(stDlistHead *dlist)
+{
+	dlist->size = 0;
+	dlist->head = NULL;
+	dlist->tail = NULL;
+	return;
+}
+
+void dlist_destory(stDlistHead *dlist)
+{
+	stDlistNode *pNode = NULL;
+	
+	while(dlist->size > 0)
+	{
+		pNode = dlist->head;
+		dlist->head = dlist->head->next;
+		free(pNode);
+		dlist->size--;
+	}
+
+	memset(dlist,0,sizeof(stDlistHead));
+
+	return;
+}
+
+int dlist_insert_head(stDlistHead *dlist,stDlistNode *pNode,int data)
+{
+   if(pNode == NULL)
+   {
+	    pNode = (stDlistNode *)malloc(sizeof(stDlistNode));
+	    if (pNode == NULL)
+	    {
+		    return -1;
+	    }
+    }
+
+    pNode->data = data;
+	pNode->prev = NULL;
+	pNode->next = NULL;
+
+	if (dlist->size == 0)
+	{
+		dlist->head = pNode;
+		dlist->tail = pNode;
+	}
+	else
+	{
+		pNode->next = dlist->head;
+		dlist->head->prev = pNode;
+		dlist->head = pNode;			
+	}
+
+	dlist->size++;
+	return 0;
+}
+
+stDlistNode * dlist_remove_tail(stDlistHead *dlist)
+{
+	stDlistNode *pNode = NULL;
+
+	if(dlist->size == 0)
+	{
+		return NULL;
+	}
+
+    pNode = dlist->tail;
+	if(dlist->size > 1)
+	{
+		dlist->tail = dlist->tail->prev;
+		dlist->tail->next = NULL;
+	}
+	else
+	{
+		dlist->head = NULL;
+		dlist->tail = NULL;
+	}
+	dlist->size--;
+	return pNode;
+}
+
+void dlist_remove_node(stDlistHead * dlist,stDlistNode *pNode)
+{
+	if ((dlist == NULL)||(pNode == NULL))
+	{
+		return;
+	}
+
+	if (dlist->head == pNode)
+	{
+		dlist->head = dlist->head->next;
+	}
+	else if (dlist->tail == pNode)
+	{
+		dlist->tail = pNode->prev;
+
+		dlist->tail->next = NULL;
+	}
+	else
+	{
+		pNode->prev->next = pNode->next;
+		pNode->next->prev = pNode->prev;
+	}
+	dlist->size--;
+	pNode->prev = NULL;
+	pNode->next = NULL;
+	
+	if (dlist->size == 0)
+	{
+		memset(dlist,0,sizeof(stDlistHead));
+	}
+
+	return;
+}
+stDlistNode * dlist_search(stDlistHead * dlist,int data)
+{
+	stDlistNode *pNode = dlist->head;
+	while(pNode != NULL)
+	{
+		if (pNode->data == data)
+		{
+			return pNode;
+		}
+		pNode = pNode->next;
+
+    }
+	return NULL;
+}
+
+void dlist_dump(stDlistHead *dlist)
+{
+	int no = 0;
+	stDlistNode *pNode = dlist->head;
+	while(pNode != NULL)
+	{
+		printf("\r\n [%d] = %d",no++,pNode->data);
+		pNode = pNode->next;
+	}
+
+	return;
+}
+
+
+void Lru_dlist(stDlistHead *dlist,int data)
+{
+	stDlistNode *pNode = NULL;
+
+	pNode = dlist_search(dlist,data);
+	if (pNode != NULL)
+	{
+		dlist_remove_node(dlist,pNode);
+	}
+	else if(dlist->size >= 4)
+	{
+		pNode = dlist_remove_tail(dlist);
+
+	}
+	
+	dlist_insert_head(dlist ,pNode,data);
+
+	return;
+}
+
+int main()
+{
+	stDlistHead dlist = {0};
+    stDlistNode * pNode = NULL;
+
+	dlist_init(&dlist);
+
+	printf("\r\n inset 1,2,3");
+	dlist_insert_head(&dlist,NULL,1);
+	dlist_insert_head(&dlist,NULL,2);
+	dlist_insert_head(&dlist,NULL,3);
+
+	dlist_dump(&dlist);
+
+	pNode = dlist_remove_tail(&dlist);
+	if(pNode != NULL)
+	{
+		printf("\r\n remove %d",pNode->data);
+	}
+	dlist_insert_head(&dlist,pNode,4);
+	dlist_dump(&dlist);
+
+    Lru_dlist(&dlist,5);
+	dlist_dump(&dlist);
+    Lru_dlist(&dlist,6);
+	dlist_dump(&dlist);
+    Lru_dlist(&dlist,7);
+	dlist_dump(&dlist);
+    Lru_dlist(&dlist,5);
+	dlist_dump(&dlist);
+
+
+
+	while(dlist.size > 0)
+	{
+	    pNode = dlist_remove_tail(&dlist);
+	    if(pNode != NULL)
+	    { 
+		    printf("\r\n remove %d",pNode->data);
+	    	free (pNode);
+    	}
+	}
+
+	return 0;
+}
diff --git a/c-cpp/06_linkedlist/Dlist/Dlist.h b/c-cpp/06_linkedlist/Dlist/Dlist.h
new file mode 100644
index 0000000..1721692
--- /dev/null
+++ b/c-cpp/06_linkedlist/Dlist/Dlist.h
@@ -0,0 +1,23 @@
+/*************************************************************************
+ > File Name: Dlist.c
+ > Author:  jinshaohui
+ > Mail:    jinshaohui789@163.com
+ > Time:    18-10-07
+ > Desc:    
+ ************************************************************************/
+#include<stdio.h>
+
+typedef struct DlistNode
+{
+	struct DlistNode *prev;
+	struct DlistNode *next;
+	int    data;
+}stDlistNode;
+
+typedef struct Dlisthead
+{
+	int size;
+	stDlistNode *head;
+	stDlistNode *tail;
+}stDlistHead;
+
diff --git a/c-cpp/09_queue/.gitkeep b/c-cpp/09_queue/.gitkeep
new file mode 100644
index 0000000..e69de29
diff --git a/c-cpp/09_queue/array_queue.hpp b/c-cpp/09_queue/array_queue.hpp
new file mode 100644
index 0000000..6bf0892
--- /dev/null
+++ b/c-cpp/09_queue/array_queue.hpp
@@ -0,0 +1,97 @@
+/**
+ * Created by Liam Huang (Liam0205) on 2018/10/10.
+ */
+
+#ifndef QUEUE_ARRAY_QUEUE_HPP_
+#define QUEUE_ARRAY_QUEUE_HPP_
+
+template <typename T>
+class ArrayQueue {
+  private:
+    T*     items_    = nullptr;
+    size_t capacity_ = 0;
+    size_t head_     = 0;
+    size_t tail_     = 0;
+
+  public:
+    ArrayQueue() = delete;
+    ArrayQueue(const size_t capacity) : capacity_(capacity) {
+        items_ = new T[capacity_];
+    }
+    ~ArrayQueue() {
+        if (nullptr != items_) {
+            delete[] items_;
+            items_ = nullptr;
+        }
+    }
+    ArrayQueue(const ArrayQueue& other) : capacity_(other.capacity_) {
+        items_ = new T[capacity_];
+        for (size_t i = other.head_; i != other.tail_; ++i) {
+            enqueue(other.items_[i]);
+        }
+    }
+    ArrayQueue& operator=(const ArrayQueue& rhs) {
+        delete[] items_;
+        head_     = 0;
+        tail_     = 0;
+        capacity_ = rhs.capacity_;
+        items_    = new T[capacity_];
+        for (size_t i = rhs.head_; i != rhs.tail_; ++i) {
+            enqueue(rhs.items_[i]);
+        }
+        return *this;
+    }
+    ArrayQueue(ArrayQueue&& other) : items_(other.items_),
+                                     capacity_(other.capacity_),
+                                     head_(other.head_),
+                                     tail_(other.tail_) {
+        other.items_    = nullptr;
+        other.capacity_ = 0;
+        other.head_     = 0;
+        other.tail_     = 0;
+    }
+    ArrayQueue& operator=(ArrayQueue&& rhs) {
+        delete[] items_;
+        items_        = rhs.items_;
+        capacity_     = rhs.capacity_;
+        head_         = rhs.head_;
+        tail_         = rhs.tail_;
+        rhs.items_    = nullptr;
+        rhs.capacity_ = 0;
+        rhs.head_     = 0;
+        rhs.tail_     = 0;
+        return *this;
+    }
+
+  public:
+    void enqueue(T item) {
+        if (capacity_ == tail_) {
+            throw "Push data into a full queue!";
+        }
+        items_[tail_++] = item;
+    }
+    T head() const {
+        if (head_ != tail_) {
+            return items_[head_];
+        } else {
+            throw "Fetch data from an empty queue!";
+        }
+    }
+    void dequeue() {
+        if (head_ != tail_) {
+            ++head_;
+        } else {
+            throw "Pop data from an empty queue!";
+        }
+    }
+
+  public:
+    template <typename UnaryFunc>
+    void traverse(UnaryFunc do_traverse) {
+        for (size_t i = head_; i != tail_; ++i) {
+            do_traverse(items_[i]);
+        }
+    }
+};
+
+#endif  // QUEUE_ARRAY_QUEUE_HPP_
diff --git a/c-cpp/09_queue/array_queue_test.cc b/c-cpp/09_queue/array_queue_test.cc
new file mode 100644
index 0000000..c2c3b3b
--- /dev/null
+++ b/c-cpp/09_queue/array_queue_test.cc
@@ -0,0 +1,56 @@
+#include <iostream>
+#include "array_queue.hpp"
+
+int main() {
+    auto do_traverse = [&](auto item){ std::cout << item << ' '; };
+
+    ArrayQueue<int> array_queue_1(3);
+    array_queue_1.enqueue(1);
+    array_queue_1.enqueue(2);
+    array_queue_1.enqueue(3);
+    // array_queue_1.enqueue(4);  // throw
+    array_queue_1.traverse(do_traverse);
+    std::cout << std::endl;
+
+    ArrayQueue<int> array_queue_2(array_queue_1);  // copy constructor
+    array_queue_2.traverse(do_traverse);
+    std::cout << std::endl;
+
+    ArrayQueue<int> array_queue_3(std::move(array_queue_2));  // move constructor
+    array_queue_3.traverse(do_traverse);
+    std::cout << std::endl;
+    array_queue_2.traverse(do_traverse);
+    std::cout << std::endl;
+
+    std::cout << array_queue_3.head() << std::endl;
+    array_queue_3.dequeue();
+    std::cout << array_queue_3.head() << std::endl;
+    array_queue_3.dequeue();
+    std::cout << array_queue_3.head() << std::endl;
+    array_queue_3.dequeue();
+    // std::cout << array_queue_3.head() << std::endl;  // throw
+    // array_queue_3.dequeue();  // throw
+
+    ArrayQueue<int> array_queue_4(1);
+    array_queue_4 = array_queue_1;  // copy assignment
+    array_queue_4.traverse(do_traverse);
+    std::cout << std::endl;
+
+    ArrayQueue<int> array_queue_5(100);
+    array_queue_5 = std::move(array_queue_4);  // move assignment
+    array_queue_5.traverse(do_traverse);
+    std::cout << std::endl;
+    array_queue_4.traverse(do_traverse);
+    std::cout << std::endl;
+
+    std::cout << array_queue_5.head() << std::endl;
+    array_queue_5.dequeue();
+    std::cout << array_queue_5.head() << std::endl;
+    array_queue_5.dequeue();
+    std::cout << array_queue_5.head() << std::endl;
+    array_queue_5.dequeue();
+    // std::cout << array_queue_5.head() << std::endl;  // throw
+    // array_queue_5.dequeue();  // throw
+
+    return 0;
+}
diff --git a/c-cpp/09_queue/block_queue.hpp b/c-cpp/09_queue/block_queue.hpp
new file mode 100644
index 0000000..d8de168
--- /dev/null
+++ b/c-cpp/09_queue/block_queue.hpp
@@ -0,0 +1,82 @@
+/**
+ * Created by Liam Huang (Liam0205) on 2018/10/11.
+ */
+
+#ifndef QUEUE_BLOCK_QUEUE_HPP_
+#define QUEUE_BLOCK_QUEUE_HPP_
+
+#include <queue>
+#include <mutex>
+#include <condition_variable>
+
+template <typename T>
+class BlockQueue {
+  public:
+    using value_type      = T;
+    using container_type  = std::queue<value_type>;
+    using size_type       = typename container_type::size_type;
+
+  private:
+    size_type capacity_ = 0;
+    container_type container_;
+    mutable std::mutex mutex_;
+    mutable std::condition_variable not_empty_;
+    mutable std::condition_variable not_full_;
+
+  public:
+    BlockQueue() = delete;
+    BlockQueue(const size_type capacity) : capacity_(capacity) {}
+    BlockQueue(const BlockQueue&) = default;
+    BlockQueue(BlockQueue&&) = default;
+    BlockQueue& operator=(const BlockQueue&) = default;
+    BlockQueue& operator=(BlockQueue&&) = default;
+
+  private:
+    bool empty() const { return container_.empty(); }
+    bool full() const { return not(container_.size() < capacity_); }
+
+  public:
+    void put(const value_type& item) {
+        std::unqiue_lock<std::mutex> lock(mutex_);
+        while (full()) {
+            not_full_.wait(lock);
+        }
+        container_.push(item);
+        not_empty_.notify_one();
+    }
+    void take(value_type& out) {
+        std::unique_lock<std::mutex> lock(mutex_);
+        while (empty()) {
+            not_empty_.wait(lock);
+        }
+        out = container_.front();
+        container_.pop();
+        not_full_.notify_one();
+    }
+    template <typename Duration>
+    bool put_for(const value_type& item, const Duration& d) {
+        std::unqiue_lock<std::mutex> lock(mutex_);
+        if (not_full_.wait_for(lock, d, [&](){ return not full(); })) {
+            container_.push(item);
+            not_empty_.notify_one();
+            return true;
+        } else {
+            return false;
+        }
+    }
+    template <typename Duration>
+    bool take_for(const Duration& d, value_type& out) {
+        std::unique_lock<std::mutex> lock(mutex_);
+        if (not_empty_.wait_for(lock, d, [&](){ return not empty(); })) {
+            out = container_.front();
+            container_.pop();
+            not_full_.notify_one();
+            return true;
+        } else {
+            return false;
+        }
+    }
+};
+
+#endif  // QUEUE_BLOCK_QUEUE_HPP_
+
diff --git a/c-cpp/09_queue/circular_queue.hpp b/c-cpp/09_queue/circular_queue.hpp
new file mode 100644
index 0000000..df4664c
--- /dev/null
+++ b/c-cpp/09_queue/circular_queue.hpp
@@ -0,0 +1,99 @@
+/**
+ * Created by Liam Huang (Liam0205) on 2018/10/10.
+ */
+
+#ifndef QUEUE_CIRCULAR_QUEUE_HPP_
+#define QUEUE_CIRCULAR_QUEUE_HPP_
+
+template <typename T>
+class CircularQueue {
+  private:
+    T*     items_    = nullptr;
+    size_t capacity_ = 0;
+    size_t head_     = 0;
+    size_t tail_     = 0;
+
+  public:
+    CircularQueue() = delete;
+    CircularQueue(const size_t capacity) : capacity_(capacity) {
+        items_ = new T[capacity_];
+    }
+    ~CircularQueue() {
+        if (nullptr != items_) {
+            delete[] items_;
+            items_ = nullptr;
+        }
+    }
+    CircularQueue(const CircularQueue& other) : capacity_(other.capacity_) {
+        items_ = new T[capacity_];
+        for (size_t i = other.head_; i != other.tail_; ++i) {
+            enqueue(other.items_[i]);
+        }
+    }
+    CircularQueue& operator=(const CircularQueue& rhs) {
+        delete[] items_;
+        head_     = 0;
+        tail_     = 0;
+        capacity_ = rhs.capacity_;
+        items_    = new T[capacity_];
+        for (size_t i = rhs.head_; i != rhs.tail_; ++i) {
+            enqueue(rhs.items_[i]);
+        }
+        return *this;
+    }
+    CircularQueue(CircularQueue&& other) : items_(other.items_),
+                                     capacity_(other.capacity_),
+                                     head_(other.head_),
+                                     tail_(other.tail_) {
+        other.items_    = nullptr;
+        other.capacity_ = 0;
+        other.head_     = 0;
+        other.tail_     = 0;
+    }
+    CircularQueue& operator=(CircularQueue&& rhs) {
+        delete[] items_;
+        items_        = rhs.items_;
+        capacity_     = rhs.capacity_;
+        head_         = rhs.head_;
+        tail_         = rhs.tail_;
+        rhs.items_    = nullptr;
+        rhs.capacity_ = 0;
+        rhs.head_     = 0;
+        rhs.tail_     = 0;
+        return *this;
+    }
+
+  public:
+    void enqueue(T item) {
+        if ((tail_ + 1) % capacity_ == head_) {
+            throw "Push data into a full queue!";
+        }
+        items_[tail_] = item;
+        tail_ = (tail_ + 1) % capacity_;
+    }
+    T head() const {
+        if (head_ != tail_) {
+            return items_[head_];
+        } else {
+            throw "Fetch data from an empty queue!";
+        }
+    }
+    void dequeue() {
+        if (head_ != tail_) {
+            head_ = (head_ + 1) % capacity_;
+        } else {
+            throw "Pop data from an empty queue!";
+        }
+    }
+
+  public:
+    template <typename UnaryFunc>
+    void traverse(UnaryFunc do_traverse) {
+        if (0 == capacity_) return;
+        for (size_t i = head_; i % capacity_ != tail_; ++i) {
+            do_traverse(items_[i % capacity_]);
+        }
+    }
+};
+
+#endif  // QUEUE_CIRCULAR_QUEUE_HPP_
diff --git a/c-cpp/09_queue/circular_queue_test.cc b/c-cpp/09_queue/circular_queue_test.cc
new file mode 100644
index 0000000..46e025a
--- /dev/null
+++ b/c-cpp/09_queue/circular_queue_test.cc
@@ -0,0 +1,62 @@
+#include <iostream>
+#include "circular_queue.hpp"
+
+int main() {
+    auto do_traverse = [&](auto item){ std::cout << item << ' '; };
+
+    CircularQueue<int> circular_queue_1(4);
+    circular_queue_1.enqueue(1);
+    circular_queue_1.enqueue(2);
+    circular_queue_1.enqueue(3);
+    // circular_queue_1.enqueue(4);  // throw
+    circular_queue_1.traverse(do_traverse);
+    std::cout << std::endl;
+
+    CircularQueue<int> circular_queue_2(circular_queue_1);  // copy constructor
+    circular_queue_2.traverse(do_traverse);
+    std::cout << std::endl;
+
+    CircularQueue<int> circular_queue_3(std::move(circular_queue_2));  // move constructor
+    circular_queue_3.traverse(do_traverse);
+    std::cout << std::endl;
+    circular_queue_2.traverse(do_traverse);
+    std::cout << std::endl;
+
+    std::cout << circular_queue_3.head() << std::endl;
+    circular_queue_3.dequeue();
+    std::cout << circular_queue_3.head() << std::endl;
+    circular_queue_3.dequeue();
+    std::cout << circular_queue_3.head() << std::endl;
+    circular_queue_3.dequeue();
+    // std::cout << circular_queue_3.head() << std::endl;  // throw
+    // circular_queue_3.dequeue();  // throw
+
+    CircularQueue<int> circular_queue_4(1);
+    circular_queue_4 = circular_queue_1;  // copy assignment
+    circular_queue_4.traverse(do_traverse);
+    std::cout << std::endl;
+
+    CircularQueue<int> circular_queue_5(100);
+    circular_queue_5 = std::move(circular_queue_4);  // move assignment
+    circular_queue_5.traverse(do_traverse);
+    std::cout << std::endl;
+    circular_queue_4.traverse(do_traverse);
+    std::cout << std::endl;
+
+    std::cout << circular_queue_5.head() << std::endl;
+    circular_queue_5.dequeue();
+    std::cout << circular_queue_5.head() << std::endl;
+    circular_queue_5.dequeue();
+    std::cout << circular_queue_5.head() << std::endl;
+    circular_queue_5.dequeue();
+    // std::cout << circular_queue_5.head() << std::endl;  // throw
+    // circular_queue_5.dequeue();  // throw
+
+    for (size_t i = 0; i != 4; ++i) {
+        circular_queue_1.dequeue();
+        circular_queue_1.enqueue(i + 4);
+        circular_queue_1.traverse(do_traverse);
+        std::cout << std::endl;
+    }
+    return 0;
+}
diff --git a/c-cpp/09_queue/concurrency_queue.hpp b/c-cpp/09_queue/concurrency_queue.hpp
new file mode 100644
index 0000000..8e9bb78
--- /dev/null
+++ b/c-cpp/09_queue/concurrency_queue.hpp
@@ -0,0 +1,85 @@
+/**
+ * Created by Liam Huang (Liam0205) on 2018/10/11.
+ */
+
+#ifndef QUEUE_CONCURRENCY_QUEUE_HPP_
+#define QUEUE_CONCURRENCY_QUEUE_HPP_
+
+#include <queue>
+#include <mutex>
+#include <condition_variable>
+#include <memory>
+
+template <typename T>
+class ConcurrencyQueue {
+  public:
+    using value_type      = T;
+    using container_type  = std::queue<value_type>;
+    using size_type       = typename container_type::size_type;
+
+  private:
+    container_type container_;
+    mutable std::mutex mutex_;
+    std::condition_variable container_cond_;
+
+  public:
+    ConcurrencyQueue() = default;
+    ConcurrencyQueue(const ConcurrencyQueue&) = default;
+    ConcurrencyQueue(ConcurrencyQueue&&) = default;
+    ConcurrencyQueue& operator=(const ConcurrencyQueue&) = default;
+    ConcurrencyQueue& operator=(ConcurrencyQueue&&) = default;
+
+  private:
+    bool empty_() const { return container_.empty(); }
+
+  public:
+    bool empty() const {
+        std::lock_guard<std::mutex> lg(mutex_);
+        return container_.empty();
+    }
+    void push(value_type item) {
+        std::lock_guard<std::mutex> lg(mutex_);
+        container_.push(std::move(item));
+        container_cond_.notify_one();
+    }
+    void wait_and_pop(value_type& out) {
+        std::unique_lock<std::mutex> lk(mutex_);
+        while (empty_()) {
+            container_cond_.wait(lk)
+        }
+        out = std::move(container_.front());
+        container_.pop();
+    }
+    std::shared_ptr<value_type> wait_and_pop() {
+        std::unique_lock<std::mutex> lk(mutex_);
+        while (empty_()) {
+            container_cond_.wait(lk)
+        }
+        auto res = std::make_shared<value_type>(std::move(container_.front()));
+        container_.pop();
+        return res;
+    }
+    bool try_pop(value_type& out) {
+        std::lock_guard<std::mutex> lg(mutex_);
+        if (empty_()) {
+            return false;
+        } else {
+            out = std::move(container_.front());
+            container_.pop();
+            return true;
+        }
+    }
+    std::shared_ptr<value_type> try_pop() {
+        std::lock_guard<std::mutex> lg(mutex_);
+        if (empty_()) {
+            return nullptr;
+        } else {
+            auto res = std::make_shared<value_type>(std::move(container_.front()));
+            container_.pop();
+            return res;
+        }
+    }
+};
+
+#endif  // QUEUE_CONCURRENCY_QUEUE_HPP_
+
diff --git a/c-cpp/09_queue/dynamic_array_queue.hpp b/c-cpp/09_queue/dynamic_array_queue.hpp
new file mode 100644
index 0000000..73939e4
--- /dev/null
+++ b/c-cpp/09_queue/dynamic_array_queue.hpp
@@ -0,0 +1,105 @@
+/**
+ * Created by Liam Huang (Liam0205) on 2018/10/10.
+ */
+
+#ifndef QUEUE_DYNAMIC_ARRAY_QUEUE_HPP_
+#define QUEUE_DYNAMIC_ARRAY_QUEUE_HPP_
+
+template <typename T>
+class DynamicArrayQueue {
+  private:
+    T*     items_    = nullptr;
+    size_t capacity_ = 0;
+    size_t head_     = 0;
+    size_t tail_     = 0;
+
+  public:
+    DynamicArrayQueue() = delete;
+    DynamicArrayQueue(const size_t capacity) : capacity_(capacity) {
+        items_ = new T[capacity_];
+    }
+    ~DynamicArrayQueue() {
+        if (nullptr != items_) {
+            delete[] items_;
+            items_ = nullptr;
+        }
+    }
+    DynamicArrayQueue(const DynamicArrayQueue& other) : capacity_(other.capacity_) {
+        items_ = new T[capacity_];
+        for (size_t i = other.head_; i != other.tail_; ++i) {
+            enqueue(other.items_[i]);
+        }
+    }
+    DynamicArrayQueue& operator=(const DynamicArrayQueue& rhs) {
+        delete[] items_;
+        head_     = 0;
+        tail_     = 0;
+        capacity_ = rhs.capacity_;
+        items_    = new T[capacity_];
+        for (size_t i = rhs.head_; i != rhs.tail_; ++i) {
+            enqueue(rhs.items_[i]);
+        }
+        return *this;
+    }
+    DynamicArrayQueue(DynamicArrayQueue&& other) : items_(other.items_),
+                                     capacity_(other.capacity_),
+                                     head_(other.head_),
+                                     tail_(other.tail_) {
+        other.items_    = nullptr;
+        other.capacity_ = 0;
+        other.head_     = 0;
+        other.tail_     = 0;
+    }
+    DynamicArrayQueue& operator=(DynamicArrayQueue&& rhs) {
+        delete[] items_;
+        items_        = rhs.items_;
+        capacity_     = rhs.capacity_;
+        head_         = rhs.head_;
+        tail_         = rhs.tail_;
+        rhs.items_    = nullptr;
+        rhs.capacity_ = 0;
+        rhs.head_     = 0;
+        rhs.tail_     = 0;
+        return *this;
+    }
+
+  public:
+    void enqueue(T item) {
+        if (capacity_ == tail_ - head_) {
+            throw "Push data into a full queue!";
+        }
+        if (capacity_ == tail_) {
+            // item transport
+            for (size_t i = head_; i != tail_; ++i) {
+                items_[i - head_] = items_[i];
+            }
+            tail_ = tail_ - head_;
+            head_ = 0;
+        }
+        items_[tail_++] = item;
+    }
+    T head() const {
+        if (head_ != tail_) {
+            return items_[head_];
+        } else {
+            throw "Fetch data from an empty queue!";
+        }
+    }
+    void dequeue() {
+        if (head_ != tail_) {
+            ++head_;
+        } else {
+            throw "Pop data from an empty queue!";
+        }
+    }
+
+  public:
+    template <typename UnaryFunc>
+    void traverse(UnaryFunc do_traverse) {
+        for (size_t i = head_; i != tail_; ++i) {
+            do_traverse(items_[i]);
+        }
+    }
+};
+
+#endif  // QUEUE_DYNAMIC_ARRAY_QUEUE_HPP_
diff --git a/c-cpp/09_queue/dynamic_array_queue_test.cc b/c-cpp/09_queue/dynamic_array_queue_test.cc
new file mode 100644
index 0000000..6580433
--- /dev/null
+++ b/c-cpp/09_queue/dynamic_array_queue_test.cc
@@ -0,0 +1,62 @@
+#include <iostream>
+#include "dynamic_array_queue.hpp"
+
+int main() {
+    auto do_traverse = [&](auto item){ std::cout << item << ' '; };
+
+    DynamicArrayQueue<int> dynamic_array_queue_1(3);
+    dynamic_array_queue_1.enqueue(1);
+    dynamic_array_queue_1.enqueue(2);
+    dynamic_array_queue_1.enqueue(3);
+    // dynamic_array_queue_1.enqueue(4);  // throw
+    dynamic_array_queue_1.traverse(do_traverse);
+    std::cout << std::endl;
+
+    DynamicArrayQueue<int> dynamic_array_queue_2(dynamic_array_queue_1);  // copy constructor
+    dynamic_array_queue_2.traverse(do_traverse);
+    std::cout << std::endl;
+
+    DynamicArrayQueue<int> dynamic_array_queue_3(std::move(dynamic_array_queue_2));  // move constructor
+    dynamic_array_queue_3.traverse(do_traverse);
+    std::cout << std::endl;
+    dynamic_array_queue_2.traverse(do_traverse);
+    std::cout << std::endl;
+
+    std::cout << dynamic_array_queue_3.head() << std::endl;
+    dynamic_array_queue_3.dequeue();
+    std::cout << dynamic_array_queue_3.head() << std::endl;
+    dynamic_array_queue_3.dequeue();
+    std::cout << dynamic_array_queue_3.head() << std::endl;
+    dynamic_array_queue_3.dequeue();
+    // std::cout << dynamic_array_queue_3.head() << std::endl;  // throw
+    // dynamic_array_queue_3.dequeue();  // throw
+
+    DynamicArrayQueue<int> dynamic_array_queue_4(1);
+    dynamic_array_queue_4 = dynamic_array_queue_1;  // copy assignment
+    dynamic_array_queue_4.traverse(do_traverse);
+    std::cout << std::endl;
+
+    DynamicArrayQueue<int> dynamic_array_queue_5(100);
+    dynamic_array_queue_5 = std::move(dynamic_array_queue_4);  // move assignment
+    dynamic_array_queue_5.traverse(do_traverse);
+    std::cout << std::endl;
+    dynamic_array_queue_4.traverse(do_traverse);
+    std::cout << std::endl;
+
+    std::cout << dynamic_array_queue_5.head() << std::endl;
+    dynamic_array_queue_5.dequeue();
+    std::cout << dynamic_array_queue_5.head() << std::endl;
+    dynamic_array_queue_5.dequeue();
+    std::cout << dynamic_array_queue_5.head() << std::endl;
+    dynamic_array_queue_5.dequeue();
+    // std::cout << dynamic_array_queue_5.head() << std::endl;  // throw
+    // dynamic_array_queue_5.dequeue();  // throw
+
+    for (size_t i = 0; i != 3; ++i) {
+        dynamic_array_queue_1.dequeue();
+        dynamic_array_queue_1.enqueue(i + 4);
+        dynamic_array_queue_1.traverse(do_traverse);
+        std::cout << std::endl;
+    }
+    return 0;
+}
diff --git a/c-cpp/09_queue/linked_queue.hpp b/c-cpp/09_queue/linked_queue.hpp
new file mode 100644
index 0000000..1372775
--- /dev/null
+++ b/c-cpp/09_queue/linked_queue.hpp
@@ -0,0 +1,75 @@
+/**
+ * Created by Liam Huang (Liam0205) on 2018/10/10.
+ */
+
+#ifndef QUEUE_LINKED_QUEUE_HPP_
+#define QUEUE_LINKED_QUEUE_HPP_
+
+#include <memory>
+
+template <typename T>
+struct Node {
+    using ptr_t = std::shared_ptr<Node<T>>;
+    T     data;
+    ptr_t next;
+
+    Node(T data_) : data(data_), next(nullptr) {}
+    Node() : next(nullptr) {}
+};
+
+template <typename T>
+class LinkedQueue {
+  public:
+    using node_type  = Node<T>;
+    using node_ptr_t = typename node_type::ptr_t;
+
+  private:
+    node_ptr_t head_        = nullptr;
+    node_ptr_t before_tail_ = nullptr;
+
+  public:
+    LinkedQueue()  = default;
+    ~LinkedQueue() = default;
+    LinkedQueue(const LinkedQueue& other) = default;
+    LinkedQueue& operator=(const LinkedQueue& rhs) = default;
+    LinkedQueue(LinkedQueue&& other) = default;
+    LinkedQueue& operator=(LinkedQueue&& rhs) = default;
+
+  public:
+    void enqueue(T item) {
+        if (nullptr == head_) {
+            head_ = std::make_shared<node_type>(item);
+            before_tail_ = head_;
+        } else {
+            before_tail_->next = std::make_shared<node_type>(item);
+            before_tail_ = before_tail_->next;
+        }
+    }
+    T head() const {
+        if (nullptr != head_) {
+            return head_->data;
+        } else {
+            throw "Fetch data from an empty queue!";
+        }
+    }
+    void dequeue() {
+        if (nullptr != head_) {
+            head_ = head_->next;
+            if (nullptr == head_) {
+                before_tail_ = nullptr;
+            }
+        } else {
+            throw "Pop data from an empty queue!";
+        }
+    }
+
+  public:
+    template <typename UnaryFunc>
+    void traverse(UnaryFunc do_traverse) {
+        for (node_ptr_t work = head_; nullptr != work; work = work->next) {
+            do_traverse(work->data);
+        }
+    }
+};
+
+#endif  // QUEUE_LINKED_QUEUE_HPP_
diff --git a/c-cpp/09_queue/linked_queue_test.cc b/c-cpp/09_queue/linked_queue_test.cc
new file mode 100644
index 0000000..04a9019
--- /dev/null
+++ b/c-cpp/09_queue/linked_queue_test.cc
@@ -0,0 +1,55 @@
+#include <iostream>
+#include "linked_queue.hpp"
+
+int main() {
+    auto do_traverse = [&](auto item){ std::cout << item << ' '; };
+
+    LinkedQueue<int> linked_queue_1;
+    linked_queue_1.enqueue(1);
+    linked_queue_1.enqueue(2);
+    linked_queue_1.enqueue(3);
+    linked_queue_1.traverse(do_traverse);
+    std::cout << std::endl;
+
+    LinkedQueue<int> linked_queue_2(linked_queue_1);  // copy constructor
+    linked_queue_2.traverse(do_traverse);
+    std::cout << std::endl;
+
+    LinkedQueue<int> linked_queue_3(std::move(linked_queue_2));  // move constructor
+    linked_queue_3.traverse(do_traverse);
+    std::cout << std::endl;
+    linked_queue_2.traverse(do_traverse);
+    std::cout << std::endl;
+
+    std::cout << linked_queue_3.head() << std::endl;
+    linked_queue_3.dequeue();
+    std::cout << linked_queue_3.head() << std::endl;
+    linked_queue_3.dequeue();
+    std::cout << linked_queue_3.head() << std::endl;
+    linked_queue_3.dequeue();
+    // std::cout << linked_queue_3.head() << std::endl;  // throw
+    // linked_queue_3.dequeue();  // throw
+
+    LinkedQueue<int> linked_queue_4;
+    linked_queue_4 = linked_queue_1;  // copy assignment
+    linked_queue_4.traverse(do_traverse);
+    std::cout << std::endl;
+
+    LinkedQueue<int> linked_queue_5;
+    linked_queue_5 = std::move(linked_queue_4);  // move assignment
+    linked_queue_5.traverse(do_traverse);
+    std::cout << std::endl;
+    linked_queue_4.traverse(do_traverse);
+    std::cout << std::endl;
+
+    std::cout << linked_queue_5.head() << std::endl;
+    linked_queue_5.dequeue();
+    std::cout << linked_queue_5.head() << std::endl;
+    linked_queue_5.dequeue();
+    std::cout << linked_queue_5.head() << std::endl;
+    linked_queue_5.dequeue();
+    // std::cout << linked_queue_5.head() << std::endl;  // throw
+    // linked_queue_5.dequeue();  // throw
+
+    return 0;
+}
diff --git a/c-cpp/09_queue/lock_free_queue.hpp b/c-cpp/09_queue/lock_free_queue.hpp
new file mode 100644
index 0000000..3f02d8a
--- /dev/null
+++ b/c-cpp/09_queue/lock_free_queue.hpp
@@ -0,0 +1,84 @@
+/**
+ * Created by Liam Huang (Liam0205) on 2018/10/11.
+ */
+
+#ifndef QUEUE_LOCK_FREE_QUEUE_HPP_
+#define QUEUE_LOCK_FREE_QUEUE_HPP_
+
+#include <memory>
+#include <atomic>
+
+template <typename T>
+class LockFreeQueue {
+  public:
+    using value_type      = T;
+
+  private:
+    struct node {
+        std::shared<value_type> data = nullptr;
+        node* next                   = nullptr;
+    };
+    std::atomic<node*> head = nullptr;
+    std::atomic<node*> tail = nullptr;
+
+  public:
+    LockFreeQueue() head(new node), tail(head.load()) {}
+    LockFreeQueue(const LockFreeQueue&) = delete;
+    LockFreeQueue(LockFreeQueue&& other) : head(other.head.load()), tail(other.tail.load()) {
+        other.head.store(nullptr);
+        other.tail.store(nullptr);
+    }
+    LockFreeQueue& operator=(const LockFreeQueue&) = delete;
+    LockFreeQueue& operator=(LockFreeQueue&& rhs) {
+        while (node* const old_head = head.load()) {
+            head.store(old_head->next);
+            delete old_head;
+        }
+        head.store(rhs.head.load());
+        tail.store(rhs.tail.load());
+        rhs.head.store(nullptr);
+        rhs.tail.store(nullptr);
+    }
+    ~LockFreeQueue() {
+        while (node* const old_head = head.load()) {
+            head.store(old_head->next);
+            delete old_head;
+        }
+    }
+
+  private:
+    node* pop_head() {
+        node* const res = head.load();
+        if (res == tail.load()) {
+            return nullptr;
+        }
+        head.store(res->next);
+        return res;
+    }
+
+  public:
+    bool empty() const {
+        return head.load() == tail.load();
+    }
+    std::shared_ptr<value_type> pop() {
+        node* old_head = pop_head();
+        if (nullptr == old_head) {
+            return nullptr;
+        } else {
+            auto res = old_head->data;
+            delete old_head;
+            return res;
+        }
+    }
+    void push(value_type new_value) {
+        auto new_data = std::make_shared<value_type>(new_value);
+        node* p = new node;
+        node* old_tail = tail.load();
+        old_tail->data.swap(new_data);
+        old_tail->next = p;
+        tail_.store(p);
+    }
+};
+
+#endif  // QUEUE_LOCK_FREE_QUEUE_HPP_
+
diff --git a/c-cpp/10_recursive/.gitkeep b/c-cpp/10_recursive/.gitkeep
new file mode 100644
index 0000000..e69de29
diff --git a/c-cpp/10_recursive/one_two_step.cc b/c-cpp/10_recursive/one_two_step.cc
new file mode 100644
index 0000000..11159c7
--- /dev/null
+++ b/c-cpp/10_recursive/one_two_step.cc
@@ -0,0 +1,71 @@
+#include <iostream>
+#include <unordered_map>
+
+class SolutionOFOneTwoStep {
+  private:
+    static std::unordered_map<size_t, size_t> result_;
+
+  public:
+    enum class POLICY {
+        RECURSIVE,
+        NONRECURSIVE
+    };
+
+  private:
+    size_t recursive(size_t steps) {
+        auto iter = result_.find(steps);
+        if (result_.end() != iter) {  // found.
+            return iter->second;
+        } else {
+            size_t res = operator()(steps - 1) + operator()(steps - 2);
+            result_.insert({steps, res});
+            return res;
+        }
+    }
+    size_t nonrecursive(size_t steps) {
+        auto iter = result_.find(steps);
+        if (result_.end() != iter) {  // found.
+            return iter->second;
+        } else {
+            size_t start;
+            for (start = steps; start != 2 and result_.end() == result_.find(start); --start) {}
+            for (size_t i = start; i != steps; ++i) {
+                result_.insert({i + 1, result_[i - 1] + result_[i]});
+            }
+            return result_[steps];
+        }
+    }
+
+  public:
+    size_t operator()(size_t steps, const POLICY policy = POLICY::RECURSIVE) {
+        if (policy == POLICY::RECURSIVE) {
+            return recursive(steps);
+        } else if (policy == POLICY::NONRECURSIVE) {
+            return nonrecursive(steps);
+        }
+    }
+    static void debug() {
+        for (auto kv : result_) {
+            std::cout << kv.first << ' ' << kv.second << std::endl;
+        }
+        std::cout << std::endl;
+    }
+};
+
+std::unordered_map<size_t, size_t> SolutionOFOneTwoStep::result_ = {{1, 1}, {2, 2}};
+
+int main() {
+    SolutionOFOneTwoStep::debug();
+
+    std::cout << SolutionOFOneTwoStep()(5, SolutionOFOneTwoStep::POLICY::RECURSIVE) << std::endl;
+    SolutionOFOneTwoStep::debug();
+
+    std::cout << SolutionOFOneTwoStep()(10, SolutionOFOneTwoStep::POLICY::NONRECURSIVE) << std::endl;
+    SolutionOFOneTwoStep::debug();
+
+    std::cout << SolutionOFOneTwoStep()(20, SolutionOFOneTwoStep::POLICY::RECURSIVE) << std::endl;
+    SolutionOFOneTwoStep::debug();
+
+    return 0;
+}
+
diff --git a/go/08_stack/StackBasedOnArray.go b/go/08_stack/StackBasedOnArray.go
index cdecbf8..27e3bec 100644
--- a/go/08_stack/StackBasedOnArray.go
+++ b/go/08_stack/StackBasedOnArray.go
@@ -28,12 +28,17 @@ func (this *ArrayStack) IsEmpty() bool {
 }
 
 func (this *ArrayStack) Push(v interface{}) {
-	this.data = append(this.data, v)
 	if this.top < 0 {
 		this.top = 0
 	} else {
 		this.top += 1
 	}
+
+	if this.top > len(this.data)-1 {
+		this.data = append(this.data, v)
+	} else {
+		this.data[this.top] = v
+	}
 }
 
 func (this *ArrayStack) Pop() interface{} {
diff --git a/go/08_stack/StackBasedOnArray_test.go b/go/08_stack/StackBasedOnArray_test.go
index 0a6ea7d..55dc800 100644
--- a/go/08_stack/StackBasedOnArray_test.go
+++ b/go/08_stack/StackBasedOnArray_test.go
@@ -6,7 +6,12 @@ func TestArrayStack_Push(t *testing.T) {
 	s := NewArrayStack()
 	s.Push(1)
 	s.Push(2)
+	t.Log(s.Pop())
 	s.Push(3)
+	t.Log(s.Pop())
+	t.Log(s.Pop())
+	s.Push(4)
+	t.Log(s.Pop())
 	s.Print()
 }
 
diff --git a/go/09_queue/CircularQueue.go b/go/09_queue/CircularQueue.go
new file mode 100644
index 0000000..c228490
--- /dev/null
+++ b/go/09_queue/CircularQueue.go
@@ -0,0 +1,72 @@
+package _9_queue
+
+import "fmt"
+
+type CircularQueue struct {
+	q        []interface{}
+	capacity int
+	head     int
+	tail     int
+}
+
+func NewCircularQueue(n int) *CircularQueue {
+	if n == 0 {
+		return nil
+	}
+	return &CircularQueue{make([]interface{}, n), n, 0, 0}
+}
+
+/*
+栈空条件：head==tail为true
+*/
+func (this *CircularQueue) IsEmpty() bool {
+	if this.head == this.tail {
+		return true
+	}
+	return false
+}
+
+/*
+栈满条件：(tail+1)%capacity==head为true
+*/
+func (this *CircularQueue) IsFull() bool {
+	if this.head == (this.tail+1)%this.capacity {
+		return true
+	}
+	return false
+}
+
+func (this *CircularQueue) EnQueue(v interface{}) bool {
+	if this.IsFull() {
+		return false
+	}
+	this.q[this.tail] = v
+	this.tail = (this.tail + 1) % this.capacity
+	return true
+}
+
+func (this *CircularQueue) DeQueue() interface{} {
+	if this.IsEmpty() {
+		return nil
+	}
+	v := this.q[this.head]
+	this.head = (this.head + 1) % this.capacity
+	return v
+}
+
+func (this *CircularQueue) String() string {
+	if this.IsEmpty() {
+		return "empty queue"
+	}
+	result := "head"
+	var i = this.head
+	for true {
+		result += fmt.Sprintf("<-%+v", this.q[i])
+		i = (i + 1) % this.capacity
+		if i == this.tail {
+			break
+		}
+	}
+	result += "<-tail"
+	return result
+}
diff --git a/go/09_queue/CircularQueue_test.go b/go/09_queue/CircularQueue_test.go
new file mode 100644
index 0000000..59c6441
--- /dev/null
+++ b/go/09_queue/CircularQueue_test.go
@@ -0,0 +1,37 @@
+package _9_queue
+
+import "testing"
+
+func TestCircularQueue_EnQueue(t *testing.T) {
+	q := NewCircularQueue(5)
+	q.EnQueue(1)
+	q.EnQueue(2)
+	q.EnQueue(3)
+	q.EnQueue(4)
+	q.EnQueue(5)
+	q.EnQueue(6)
+	t.Log(q)
+}
+
+func TestCircularQueue_DeQueue(t *testing.T) {
+	q := NewCircularQueue(5)
+	q.EnQueue(1)
+	q.EnQueue(2)
+	q.EnQueue(3)
+	q.EnQueue(4)
+	q.EnQueue(5)
+	q.EnQueue(6)
+	t.Log(q)
+	t.Log(q.DeQueue())
+	t.Log(q)
+	q.EnQueue(5)
+	t.Log(q)
+	q.DeQueue()
+	t.Log(q)
+	q.DeQueue()
+	t.Log(q)
+	q.DeQueue()
+	t.Log(q)
+	q.DeQueue()
+	t.Log(q)
+}
diff --git a/go/09_queue/QueueBasedOnArray.go b/go/09_queue/QueueBasedOnArray.go
new file mode 100644
index 0000000..d70335f
--- /dev/null
+++ b/go/09_queue/QueueBasedOnArray.go
@@ -0,0 +1,44 @@
+package _9_queue
+
+import "fmt"
+
+type ArrayQueue struct {
+	q        []interface{}
+	capacity int
+	head     int
+	tail     int
+}
+
+func NewArrayQueue(n int) *ArrayQueue {
+	return &ArrayQueue{make([]interface{}, n), n, 0, 0}
+}
+
+func (this *ArrayQueue) EnQueue(v interface{}) bool {
+	if this.tail == this.capacity {
+		return false
+	}
+	this.q[this.tail] = v
+	this.tail++
+	return true
+}
+
+func (this *ArrayQueue) DeQueue() interface{} {
+	if this.head == this.tail {
+		return nil
+	}
+	v := this.q[this.head]
+	this.head++
+	return v
+}
+
+func (this *ArrayQueue) String() string {
+	if this.head == this.tail {
+		return "empty queue"
+	}
+	result := "head"
+	for i := this.head; i <= this.tail-1; i++ {
+		result += fmt.Sprintf("<-%+v", this.q[i])
+	}
+	result += "<-tail"
+	return result
+}
diff --git a/go/09_queue/QueueBasedOnArray_test.go b/go/09_queue/QueueBasedOnArray_test.go
new file mode 100644
index 0000000..50335f7
--- /dev/null
+++ b/go/09_queue/QueueBasedOnArray_test.go
@@ -0,0 +1,35 @@
+package _9_queue
+
+import "testing"
+
+func TestArrayQueue_EnQueue(t *testing.T) {
+	q := NewArrayQueue(5)
+	q.EnQueue(1)
+	q.EnQueue(2)
+	q.EnQueue(3)
+	q.EnQueue(4)
+	q.EnQueue(5)
+	q.EnQueue(6)
+	t.Log(q)
+}
+
+func TestArrayQueue_DeQueue(t *testing.T) {
+	q := NewArrayQueue(5)
+	q.EnQueue(1)
+	q.EnQueue(2)
+	q.EnQueue(3)
+	q.EnQueue(4)
+	q.EnQueue(5)
+	q.EnQueue(6)
+	t.Log(q)
+	q.DeQueue()
+	t.Log(q)
+	q.DeQueue()
+	t.Log(q)
+	q.DeQueue()
+	t.Log(q)
+	q.DeQueue()
+	t.Log(q)
+	q.DeQueue()
+	t.Log(q)
+}
diff --git a/go/09_queue/QueueBasedOnLinkedList.go b/go/09_queue/QueueBasedOnLinkedList.go
new file mode 100644
index 0000000..65d898d
--- /dev/null
+++ b/go/09_queue/QueueBasedOnLinkedList.go
@@ -0,0 +1,52 @@
+package _9_queue
+
+import "fmt"
+
+type ListNode struct {
+	val  interface{}
+	next *ListNode
+}
+
+type LinkedListQueue struct {
+	head   *ListNode
+	tail   *ListNode
+	length int
+}
+
+func NewLinkedListQueue() *LinkedListQueue {
+	return &LinkedListQueue{nil, nil, 0}
+}
+
+func (this *LinkedListQueue) EnQueue(v interface{}) {
+	node := &ListNode{v, nil}
+	if nil == this.tail {
+		this.tail = node
+		this.head = node
+	} else {
+		this.tail.next = node
+		this.tail = node
+	}
+	this.length++
+}
+
+func (this *LinkedListQueue) DeQueue() interface{} {
+	if this.head == nil {
+		return nil
+	}
+	v := this.head.val
+	this.head = this.head.next
+	this.length--
+	return v
+}
+
+func (this *LinkedListQueue) String() string {
+	if this.head == nil {
+		return "empty queue"
+	}
+	result := "head<-"
+	for cur := this.head; cur != nil; cur = cur.next {
+		result += fmt.Sprintf("<-%+v", cur.val)
+	}
+	result += "<-tail"
+	return result
+}
diff --git a/go/09_queue/QueueBasedOnLinkedList_test.go b/go/09_queue/QueueBasedOnLinkedList_test.go
new file mode 100644
index 0000000..425c6e8
--- /dev/null
+++ b/go/09_queue/QueueBasedOnLinkedList_test.go
@@ -0,0 +1,35 @@
+package _9_queue
+
+import "testing"
+
+func TestListQueue_EnQueue(t *testing.T) {
+	q := NewLinkedListQueue()
+	q.EnQueue(1)
+	q.EnQueue(2)
+	q.EnQueue(3)
+	q.EnQueue(4)
+	q.EnQueue(5)
+	q.EnQueue(6)
+	t.Log(q)
+}
+
+func TestListQueue_DeQueue(t *testing.T) {
+	q := NewLinkedListQueue()
+	q.EnQueue(1)
+	q.EnQueue(2)
+	q.EnQueue(3)
+	q.EnQueue(4)
+	q.EnQueue(5)
+	q.EnQueue(6)
+	t.Log(q)
+	q.DeQueue()
+	t.Log(q)
+	q.DeQueue()
+	t.Log(q)
+	q.DeQueue()
+	t.Log(q)
+	q.DeQueue()
+	t.Log(q)
+	q.DeQueue()
+	t.Log(q)
+}
diff --git a/java/05_array/Array.java b/java/05_array/Array.java
index 6b7ad05..8ec2fe1 100644
--- a/java/05_array/Array.java
+++ b/java/05_array/Array.java
@@ -11,14 +11,14 @@ public class Array {
     public int data[];
     //定义数组长度
     private int n;
-    //定义中保存的数据个数
+    //定义中实际个数
     private int count;
 
     //构造方法，定义数组大小
     public Array(int capacity){
-        this.data = new int[]{0,1,2,3,4};
+        this.data = new int[capacity];
         this.n = capacity;
-        this.count=capacity;
+        this.count=0;//一开始一个数都没有存所以为0
     }
 
     //根据索引，找到数据中的元素并返回
@@ -49,13 +49,14 @@ public class Array {
     //向数组中插入一个元素
     public boolean insert(int index, int value){
         if (index<0 || index>=count) return false;
-//        if (count == n) return false;不是太懂
-        //数组长度增加1
-        int[] arr = new int[count+1];
+        //当实际存储的个数等于数组的最大长度就不让新增
+        if (count == n) return false;
+        //数组长度增加1。不需要初始化
+        /*int[] arr = new int[count+1];
         for (int i = 0; i < data.length; i++) {
             arr[i] = data[i];
         }
-        data=arr;
+        data=arr;*/
 
         for (int i = count-1; i>=index; --i){
             data[i+1] = data[i];
@@ -66,13 +67,15 @@ public class Array {
     }
 
     public boolean insertToTail(int value) {
-//        if (count == n) return false;不是太懂
+        
+        //当实际存储的个数等于数组的最大长度就不让新增
+        if (count == n) return false;
         //数组长度增加1
-        int[] arr = new int[count+1];
+        /*int[] arr = new int[count+1];
         for (int i = 0; i < data.length; i++) {
             arr[i] = data[i];
         }
-        data=arr;
+        data=arr;*/
         data[count++] = value;
         return true;
     }
diff --git a/java/09_queue/CircularQueue.java b/java/09_queue/CircularQueue.java
index c3c54cc..71a988c 100644
--- a/java/09_queue/CircularQueue.java
+++ b/java/09_queue/CircularQueue.java
@@ -36,7 +36,8 @@ public class CircularQueue {
   }
 
   public void printAll() {
-    for (int i = head; i < tail; ++i) {
+    if (0 == n) return;
+    for (int i = head; i % n != tail; ++i) {
       System.out.print(items[i] + " ");
     }
     System.out.println();
diff --git a/java/09_queue/DynimacArrayQueue.java b/java/09_queue/DynamicArrayQueue.java
similarity index 94%
rename from java/09_queue/DynimacArrayQueue.java
rename to java/09_queue/DynamicArrayQueue.java
index 3a19fa3..9faad0f 100644
--- a/java/09_queue/DynimacArrayQueue.java
+++ b/java/09_queue/DynamicArrayQueue.java
@@ -3,7 +3,7 @@ package queue;
 /**
  * Created by wangzheng on 2018/10/9.
  */
-public class DynimacArrayQueue {
+public class DynamicArrayQueue {
   // 数组：items，数组大小：n
   private String[] items;
   private int n = 0;
@@ -12,7 +12,7 @@ public class DynimacArrayQueue {
   private int tail = 0;
 
   // 申请一个大小为capacity的数组
-  public DynimacArrayQueue(int capacity) {
+  public DynamicArrayQueue(int capacity) {
     items = new String[capacity];
     n = capacity;
   }
diff --git a/javascript/07_linkedlist/LinkedListAlgo.js b/javascript/07_linkedlist/LinkedListAlgo.js
index 39cf6e4..77695c9 100644
--- a/javascript/07_linkedlist/LinkedListAlgo.js
+++ b/javascript/07_linkedlist/LinkedListAlgo.js
@@ -33,7 +33,7 @@ class LinkedList {
             currentNode = currentNode.next
             pos++
         }
-        return currentNode === null ? -1 : pos
+        return currentNode === null ? -1 : currentNode
     }
     // 指定元素向后插入
     insert(newElement, element) {
@@ -69,6 +69,9 @@ class LinkedList {
     }
     // 遍历显示所有节点
     display() {
+        //先检查是否为环
+        if(this.checkCircle()) return false
+
         let currentNode = this.head
         while (currentNode !== null) {
             console.log(currentNode.element)
@@ -89,6 +92,30 @@ class LinkedList {
         this.head = root
     }
 
+    //增强尾插法可读性，便于初学者理解
+    reverseList1(){
+      //head节点即哨兵，作用就是使所有链表，
+      // 包括空链表的头节点不为null,并使对单链表的插入、删除操作不需要区分是否为空表或是否在第一个位置进行，
+      // 从而与其他位置的插入、删除操作一致
+      //所以反转链表的时候不需要带上head节点
+      let currentNode=this.head.next
+      //第一个节点头结点让其指向null
+      let previousNode=null
+      while(currentNode!==null){
+        //务必先保留下一节点的指针地址
+        let nextNode=currentNode.next
+        //第一次是null
+        currentNode.next=previousNode
+        //此时将previousNode赋值为当前节点，
+        // 那么下次循环的时候，方便下次的currentNode指向previousNode
+        previousNode=currentNode
+        //抬走，下一个！
+        currentNode=nextNode
+      }
+    //最后将反转好的链表加上头节点
+    this.head.next=previousNode
+    }
+
     // 自己一开始瞎想的。差距啊
     reverseList2() {
         let currentNode = this.head.next
@@ -122,6 +149,8 @@ class LinkedList {
     }
     // 删除倒数第k个节点
     removeByIndexFromEnd(index) {
+        //务必先判断是否是 环链表
+        if(this.checkCircle()) return false
         let pos = 1
         this.reverseList()
         let currentNode = this.head.next
diff --git a/javascript/08_stack/SampleBrowser.js b/javascript/08_stack/SampleBrowser.js
new file mode 100644
index 0000000..c084dd7
--- /dev/null
+++ b/javascript/08_stack/SampleBrowser.js
@@ -0,0 +1,56 @@
+/**
+ * 使用前后栈实现浏览器的前进后退。
+ * 
+ * Author nameczz
+ */
+const stack = require('./StackBasedOnLinkedList')
+
+class SampleBrowser {
+    constructor() {
+        this.normalStack = new stack.CreatedStack()
+        this.backStack = new stack.CreatedStack()
+    }
+    // 正常浏览页面
+    pushNormal(name) {
+        this.normalStack.push(name)
+        this.backStack.clear()
+        this.displayAllStack()
+    }
+    // 后退
+    back() {
+        const value = this.normalStack.pop()
+        if (value !== -1) {
+            this.backStack.push(value)
+            this.displayAllStack()
+        } else {
+            console.log('无法后退')
+        }
+    }
+    // 前进
+    front() {
+        const value = this.backStack.pop()
+        if (value !== -1) {
+            this.normalStack.push(value)
+            this.displayAllStack()
+        } else {
+            console.log('无法前进')
+        }
+    }
+    // 打印栈内数据
+    displayAllStack() {
+        console.log('---后退页面---')
+        this.backStack.display()
+        console.log('---浏览页面---')
+        this.normalStack.display()
+    }
+}
+// Test
+const browser = new SampleBrowser()
+browser.pushNormal('www.google.com')
+browser.pushNormal('www.baidu.com')
+browser.pushNormal('www.github.com')
+// 后退
+browser.back()
+browser.back()
+browser.front()
+browser.pushNormal('www.new.com')
\ No newline at end of file
diff --git a/javascript/08_stack/StackBasedOnLinkedList.js b/javascript/08_stack/StackBasedOnLinkedList.js
new file mode 100644
index 0000000..07acc0e
--- /dev/null
+++ b/javascript/08_stack/StackBasedOnLinkedList.js
@@ -0,0 +1,62 @@
+/**
+ * 基于链表实现的栈。
+ *
+ * Author: nameczz
+ */
+
+class Node {
+    constructor(element) {
+        this.element = element
+        this.next = null
+    }
+}
+
+class StackBasedLinkedList {
+    constructor() {
+        this.top = null
+    }
+    push(value) {
+        const node = new Node(value)
+        if (this.top === null) {
+            this.top = node
+        } else {
+            node.next = this.top
+            this.top = node
+        }
+    }
+    pop() {
+        if (this.top === null) {
+            return -1
+        }
+        const value = this.top.element
+        this.top = this.top.next
+        return value
+    }
+    // 为了实现浏览器前进后退
+    clear() {
+        this.top = null
+    }
+    display() {
+        if (this.top !== null) {
+            let temp = this.top
+            while (temp !== null) {
+                console.log(temp.element)
+                temp = temp.next
+            }
+        }
+    }
+}
+// Test
+const newStack = new StackBasedLinkedList()
+newStack.push(1)
+newStack.push(2)
+newStack.push(3)
+// 获取元素
+let res = 0
+console.log('-------获取pop元素------')
+while (res !== -1) {
+    res = newStack.pop()
+    console.log(res)
+}
+
+exports.CreatedStack = StackBasedLinkedList
\ No newline at end of file
diff --git a/javascript/09_queue/CircularQueueBasedOnLinkedList.js b/javascript/09_queue/CircularQueueBasedOnLinkedList.js
new file mode 100644
index 0000000..a94f46d
--- /dev/null
+++ b/javascript/09_queue/CircularQueueBasedOnLinkedList.js
@@ -0,0 +1,71 @@
+/**
+ * 基于链表实现的循环队列。
+ *
+ * Author: nameczz
+ */
+
+class Node {
+    constructor(element) {
+        this.element = element
+        this.next = null
+    }
+}
+
+class CircularQueue {
+    constructor() {
+        this.head = null
+        this.tail = null
+    }
+
+    enqueue(value) {
+        if (this.head === null) {
+            this.head = new Node(value)
+            this.head.next = this.head
+            this.tail = this.head
+        } else {
+            const flag = this.head === this.tail
+            this.tail.next = new Node(value)
+            this.tail.next.next = this.head
+            this.tail = this.tail.next
+            if (flag) {
+                this.head.next = this.tail
+            }
+        }
+    }
+
+    dequeue() {
+        if (this.head === this.tail) {
+            const value = this.head.element
+            this.head = null
+            return value
+        } else if (this.head !== null) {
+            const value = this.head.element
+            this.head = this.head.next
+            this.tail.next = this.head
+            return value
+        } else {
+            return -1
+        }
+    }
+
+    display() {
+        let res = 0
+        console.log('-------获取dequeue元素------')
+        while (res !== -1) {
+            res = this.dequeue()
+            console.log(res)
+        }
+    }
+}
+// Test
+const newCircularQueue = new CircularQueue()
+// 插入元素
+newCircularQueue.enqueue(1)
+newCircularQueue.enqueue(2)
+newCircularQueue.enqueue(3)
+// 获取元素
+newCircularQueue.display()
+newCircularQueue.enqueue(1)
+newCircularQueue.display()
+
+// exports.CreatedStack = StackBasedLinkedList
\ No newline at end of file
diff --git a/javascript/09_queue/QueueBasedOnLinkedList.js b/javascript/09_queue/QueueBasedOnLinkedList.js
new file mode 100644
index 0000000..7591858
--- /dev/null
+++ b/javascript/09_queue/QueueBasedOnLinkedList.js
@@ -0,0 +1,52 @@
+/**
+ * 基于链表实现的队列。
+ *
+ * Author: nameczz
+ */
+
+class Node {
+    constructor(element) {
+        this.element = element
+        this.next = null
+    }
+}
+
+class QueueBasedOnLinkedList {
+    constructor() {
+        this.head = null
+        this.tail = null
+    }
+
+    enqueue(value) {
+        if (this.head === null) {
+            this.head = new Node(value)
+            this.tail = this.head
+        } else {
+            this.tail.next = new Node(value)
+            this.tail = this.tail.next
+        }
+    }
+
+    dequeue() {
+        if (this.head !== null) {
+            const value = this.head.element
+            this.head = this.head.next
+            return value
+        } else {
+            return -1
+        }
+    }
+}
+// Test
+const newQueue = new QueueBasedOnLinkedList()
+// 插入元素
+newQueue.enqueue(1)
+newQueue.enqueue(2)
+newQueue.enqueue(3)
+// 获取元素
+let res = 0
+console.log('-------获取dequeue元素------')
+while (res !== -1) {
+    res = newQueue.dequeue()
+    console.log(res)
+}
diff --git a/notes/.gitkeep b/notes/.gitkeep
new file mode 100644
index 0000000..e69de29
diff --git a/notes/10_recursion/readme.md b/notes/10_recursion/readme.md
new file mode 100644
index 0000000..29478b1
--- /dev/null
+++ b/notes/10_recursion/readme.md
@@ -0,0 +1,28 @@
+# 递归
+
+## 三个条件
+
+* 可分解为子问题
+* 子问题与原问题解法一致，只有规模上的不同
+* 有终止条件
+
+## 写递归代码
+
+* 整理出递推公式
+* 确定好终止条件
+* 「翻译」成代码
+
+关键：
+
+> 只要遇到递归，我们就把它抽象成一个递推公式，不用想一层层的调用关系，不要试图用人脑去分解每一个步骤。
+
+## 警惕
+
+* 堆栈溢出 <- 递归深度过大
+* 重复计算 <- 递归过程中的不同分支，重复计算相同子问题
+  * 保存子问题结果（map/dict）
+* 空间复杂度高 <- 递归函数调用带来的消耗
+
+## 递归改写非递归
+
+本质：人肉模拟函数调用堆栈。
diff --git a/php/06_linkedlist/SingleLinkedList.php b/php/06_linkedlist/SingleLinkedList.php
index 5928860..222f638 100644
--- a/php/06_linkedlist/SingleLinkedList.php
+++ b/php/06_linkedlist/SingleLinkedList.php
@@ -133,7 +133,7 @@ class SingleLinkedList
         $preNode = $this->head;
         // 遍历找到前置节点 要用全等判断是否是同一个对象
         // http://php.net/manual/zh/language.oop5.object-comparison.php
-        while ($curNode !== $node) {
+        while ($curNode !== $node && $curNode != null) {
             $preNode = $curNode;
             $curNode = $curNode->next;
         }
diff --git a/php/08_stack/.gitkeep b/php/08_stack/.gitkeep
new file mode 100644
index 0000000..e69de29
diff --git a/php/08_stack/StackOnLinkedList.php b/php/08_stack/StackOnLinkedList.php
new file mode 100644
index 0000000..bfac655
--- /dev/null
+++ b/php/08_stack/StackOnLinkedList.php
@@ -0,0 +1,159 @@
+<?php
+/**
+ * User: lide01
+ * Date: 2018/10/11 19:37
+ * Desc:
+ */
+
+namespace Algo_08;
+
+
+use Algo_06\SingleLinkedListNode;
+
+class StackOnLinkedList
+{
+    /**
+     * 头指针
+     *
+     * @var SingleLinkedListNode
+     */
+    public $head;
+
+    /**
+     * 栈长度
+     *
+     * @var
+     */
+    public $length;
+
+    /**
+     *
+     * StackOnLinkedList constructor.
+     */
+    public function __construct()
+    {
+        $this->head = new SingleLinkedListNode();
+        $this->length = 0;
+    }
+
+    /**
+     * 出栈
+     *
+     * @return bool
+     */
+    public function pop()
+    {
+        if (0 == $this->length) {
+            return false;
+        }
+
+        $this->head->next = $this->head->next->next;
+        $this->length--;
+
+        return true;
+    }
+
+    /**
+     * 入栈
+     *
+     * @param $data
+     *
+     * @return SingleLinkedListNode|bool
+     */
+    public function push($data)
+    {
+        return $this->pushData($data);
+    }
+
+    /**
+     * 入栈 node
+     *
+     * @param SingleLinkedListNode $node
+     *
+     * @return bool
+     */
+    public function pushNode(SingleLinkedListNode $node)
+    {
+        if (null == $node) {
+            return false;
+        }
+
+        $node->next = $this->head->next;
+        $this->head->next = $node;
+
+        $this->length++;
+        return true;
+    }
+
+    /**
+     * 入栈 data
+     *
+     * @param $data
+     *
+     * @return SingleLinkedListNode|bool
+     */
+    public function pushData($data)
+    {
+        $node = new SingleLinkedListNode($data);
+
+        if (!$this->pushNode($node)) {
+            return false;
+        }
+
+        return $node;
+    }
+
+    /**
+     * 获取栈顶元素
+     *
+     * @return SingleLinkedListNode|bool|null
+     */
+    public function top()
+    {
+        if (0 == $this->length) {
+            return false;
+        }
+
+        return $this->head->next;
+    }
+
+    /**
+     * 打印栈
+     */
+    public function printSelf()
+    {
+        if (0 == $this->length) {
+            echo 'empty stack' . PHP_EOL;
+            return;
+        }
+
+        echo 'head.next -> ';
+        $curNode = $this->head;
+        while ($curNode->next) {
+            echo $curNode->next->data . ' -> ';
+
+            $curNode = $curNode->next;
+        }
+        echo 'NULL' . PHP_EOL;
+    }
+
+    /**
+     * 获取栈长度
+     *
+     * @return int
+     */
+    public function getLength()
+    {
+        return $this->length;
+    }
+
+    /**
+     * 判断栈是否为空
+     *
+     * @return bool
+     */
+    public function isEmpty()
+    {
+        return $this->length > 0 ? false : true;
+    }
+}
\ No newline at end of file
diff --git a/php/08_stack/main.php b/php/08_stack/main.php
new file mode 100644
index 0000000..6347821
--- /dev/null
+++ b/php/08_stack/main.php
@@ -0,0 +1,32 @@
+<?php
+/**
+ * User: lide01
+ * Date: 2018/10/11 20:01
+ * Desc:
+ */
+
+namespace Algo_08;
+
+require_once '../vendor/autoload.php';
+
+$stack = new StackOnLinkedList();
+$stack->pushData(1);
+$stack->pushData(2);
+$stack->pushData(3);
+$stack->pushData(4);
+var_dump($stack->getLength());
+$stack->printSelf();
+
+$topNode = $stack->top();
+var_dump($topNode->data);
+
+$stack->pop();
+$stack->printSelf();
+$stack->pop();
+$stack->printSelf();
+
+var_dump($stack->getLength());
+
+$stack->pop();
+$stack->pop();
+$stack->printSelf();
\ No newline at end of file
diff --git a/php/README.md b/php/README.md
index 3aa9674..6a6fa5d 100644
--- a/php/README.md
+++ b/php/README.md
@@ -1,16 +1,20 @@
 ## 数据结构与算法之美PHP实现
 
 ### 项目运行
-* 依赖composer自动加载，php目录下执行`composer dump-autoload`
+* 依赖composer自动加载，php目录下执行`composer dump-autoload` || `sh buildAutoLoad.sh`
 * 项目代码均在mac&php7环境下跑通
 
 ### 项目实现
-#### 06
+#### 06_linkedlist
 * 单链表php实现
 * 回文判断
-#### 07
+
+#### 07_linkedlist
 * reverse 单链表反转
 * checkCircle 链表中环的检测
 * mergerSortedList 两个有序的链表合并
 * deleteLastKth 删除链表倒数第n个结点
-* findMiddleNode 求链表的中间结点
\ No newline at end of file
+* findMiddleNode 求链表的中间结点
+
+#### 08_stack
+* 链栈实现
\ No newline at end of file
diff --git a/php/Stack/Compute.php b/php/Stack/Compute.php
new file mode 100644
index 0000000..3e5624b
--- /dev/null
+++ b/php/Stack/Compute.php
@@ -0,0 +1,78 @@
+<?php
+
+
+
+// 四则运算 +-*/()
+function expression($str)
+{
+    $str = str_replace(' ','',$str);
+    $arr = preg_split('/([\+\-\*\/\(\)])/', $str, -1, PREG_SPLIT_DELIM_CAPTURE | PREG_SPLIT_NO_EMPTY);
+
+    $numStack = [];  // 存放数字
+    $operStack = []; // 存放运算符
+    $operStack[] = NULL;
+
+    for ($i = 0; $i < count($arr); $i++){
+        if (ord($arr[$i]) >= 48 && ord($arr[$i] <= 57)){
+            array_push($numStack, $arr[$i]);
+            continue;
+        }
+        switch ($arr[$i]){
+            case '+':
+            case '-':
+                $arrLen = count($operStack);
+                while ($operStack[$arrLen-1] === '*' || $operStack[$arrLen-1] === '/' || $operStack[$arrLen-1] === '-'){
+                    compute($numStack, $operStack);
+                    $arrLen--;
+                }
+                array_push($operStack, $arr[$i]);
+                break;
+            case '*':
+            case '/':
+            case '(':
+                array_push($operStack, $arr[$i]);
+                break;
+            case ')':
+                $arrLen = count($operStack);
+                while ($operStack[$arrLen-1] !== '('){
+                    compute($numStack, $operStack);
+                    $arrLen--;
+                }
+                array_pop($operStack);
+                break;
+            default:
+                throw new \Exception("不支持的运算符", 1);
+                break;
+        }
+    }
+    
+    $arrLen = count($operStack);
+    while ($operStack[$arrLen-1] !== NULL){  
+        compute($numStack, $operStack);
+        $arrLen--;
+    }
+    echo array_pop($numStack);
+}
+
+//数字栈长度减一，运算符栈长度减一
+function compute(&$numStack, &$operStack){
+    $num = array_pop($numStack);
+    switch (array_pop($operStack)) {
+        case '*':
+            array_push($numStack, array_pop($numStack) * $num);
+            break;
+        case '/':
+            array_push($numStack, array_pop($numStack) / $num);
+            break;
+        case '+':
+            array_push($numStack, array_pop($numStack) + $num);
+            break;
+        case '-':
+            array_push($numStack, array_pop($numStack) - $num);
+            break;
+        
+    }
+}
+expression('-1+2-(1+2*3)');
+echo PHP_EOL;
+eval('echo -1+2-(1+2*3);');
\ No newline at end of file
diff --git a/php/composer.json b/php/composer.json
index ea60240..01f6f02 100644
--- a/php/composer.json
+++ b/php/composer.json
@@ -6,7 +6,8 @@
     "autoload": {
         "psr-4": {
             "Algo_06\\": "06_linkedlist/",
-            "Algo_07\\": "07_linkedlist/"
+            "Algo_07\\": "07_linkedlist/",
+            "Algo_08\\": "08_stack/"
         }
     }
 }
diff --git a/python/05_array/myarray.py b/python/05_array/myarray.py
index af55480..e4df25b 100644
--- a/python/05_array/myarray.py
+++ b/python/05_array/myarray.py
@@ -39,7 +39,10 @@ class MyArray:
 
     def insert_to_tail(self, value: int) -> bool:
         if self._count == self._capacity: return False
-        self._data.append(value)
+        if self._count == len(self._data):
+            self._data.append(value) 
+        else:
+            self._data[self._count] = value
         self._count += 1
         return True
     
@@ -57,4 +60,6 @@ if __name__ == "__main__":
         a.insert_to_tail(i)
     
     a.delete(2)
+    print(a)
+    a.insert_to_tail(7)
     print(a)
\ No newline at end of file
diff --git a/python/07_linkedlist/linked_list_algo.py b/python/07_linkedlist/linked_list_algo.py
index 9427126..4d69ae8 100644
--- a/python/07_linkedlist/linked_list_algo.py
+++ b/python/07_linkedlist/linked_list_algo.py
@@ -55,7 +55,7 @@ def merge_sorted_list(l1: Node, l2: Node) -> Optional[Node]:
             current = current._next
         current._next = p1 if p1 else p2
         return fake_head._next
-    return p1 or p2
+    return l1 or l2
 
 # Remove nth node from the end
 # 删除倒数第n个节点。假设n大于0
diff --git a/python/09_queue/array_queue.py b/python/09_queue/array_queue.py
index 40f34c2..1b1252e 100644
--- a/python/09_queue/array_queue.py
+++ b/python/09_queue/array_queue.py
@@ -16,9 +16,16 @@ class ArrayQueue:
         self._tail = 0
 
     def enqueue(self, item: str) -> bool:
-        if self._tail == self._capacity: return False
+        if self._tail == self._capacity:
+            if self._head == 0:
+                return False
+            else:
+                for i in range(0, self._tail - self._head):
+                    self._data[i] = self._items[i + self._head]
+                self._tail = self._tail - self._head
+                self._head = 0
         
-        self._items.append(item)
+        self._items.insert(self._tail, item)
         self._tail += 1
         return True
     
diff --git a/python/09_queue/dynamic_array_queue.py b/python/09_queue/dynamic_array_queue.py
new file mode 100644
index 0000000..b422840
--- /dev/null
+++ b/python/09_queue/dynamic_array_queue.py
@@ -0,0 +1,51 @@
+"""
+    Author: Wenru
+"""
+
+from typing import Optional
+
+class DynamicArrayQueue:
+
+    def __init__(self, capacity: int):
+        self._items = []
+        self._capacity = capacity
+        self._head = 0
+        self._tail = 0
+    
+    def enqueue(self, item: str) -> bool:
+        if self._tail == self._capacity:
+            if self._head == 0: return False
+            
+            self._items[0 : self._tail - self._head] = self._items[self._head : self._tail]
+            self._tail -= self._head
+            self._head = 0
+        
+        if self._tail == len(self._items):
+            self._items.append(item)
+        else:
+            self._items[self._tail] = item
+        self._tail += 1
+        return True
+
+    def dequeue(self) -> Optional[str]:
+        if self._head != self._tail:
+            item = self._items[self._head]
+            self._head += 1
+            return item
+    
+    def __repr__(self) -> str:
+        return " ".join(item for item in self._items[self._head:self._tail])
+
+if __name__ == "__main__":
+    q = DynamicArrayQueue(10)
+    for i in range(10):
+        q.enqueue(str(i))
+    print(q)
+
+    for _ in range(3):
+        q.dequeue()
+    print(q)
+
+    q.enqueue("7")
+    q.enqueue("8")
+    print(q)
\ No newline at end of file
diff --git a/python/09_queue/linked_queue.py b/python/09_queue/linked_queue.py
new file mode 100644
index 0000000..4ee4ecf
--- /dev/null
+++ b/python/09_queue/linked_queue.py
@@ -0,0 +1,58 @@
+"""
+    Queue based upon linked list
+
+    Author: Wenru
+"""
+
+from typing import Optional
+
+class Node:
+    
+    def __init__(self, data: str, next=None):
+        self.data = data
+        self._next = next
+
+class LinkedQueue:
+
+    def __init__(self):
+        self._head: Optional[Node] = None
+        self._tail: Optional[Node] = None
+    
+    def enqueue(self, value: str):
+        new_node = Node(value)
+        if self._tail:
+            self._tail._next = new_node
+        else:
+            self._head = new_node
+        self._tail = new_node
+    
+    def dequeue(self) -> Optional[str]:
+        if self._head:
+            value = self._head.data
+            self._head = self._head._next
+            if not self._head:
+                self._tail = None
+            return value
+    
+    def __repr__(self) -> str:
+        values = []
+        current = self._head
+        while current:
+            values.append(current.data)
+            current = current._next
+        return "->".join(value for value in values)
+
+
+if __name__ == "__main__":
+    q = LinkedQueue()
+    for i in range(10):
+        q.enqueue(str(i))
+    print(q)
+
+    for _ in range(3):
+        q.dequeue()
+    print(q)
+
+    q.enqueue("7")
+    q.enqueue("8")
+    print(q)
diff --git a/swift/05_array/MyArray.swift b/swift/05_array/MyArray.swift
new file mode 100644
index 0000000..42a135b
--- /dev/null
+++ b/swift/05_array/MyArray.swift
@@ -0,0 +1,77 @@
+//
+// Created by Jiandan on 2018/10/10.
+// Copyright (c) 2018 Jiandan. All rights reserved.
+//
+
+import Foundation
+
+// <Element> Swift 泛型，此数组支持不同数据类型
+public struct MyArray<Element> {
+    private var data: [Element]
+    private var capacity = 0 // 数组长度
+    private var count = 0 // 已保存的数据个数
+
+    /// 构造方法
+    /// - parameter defaultElement: 默认元素，用来占位
+    /// - parameter capacity: 数组长度
+    init(defaultElement: Element, capacity: Int) {
+        data = [Element](repeating: defaultElement, count: capacity)
+        self.capacity = capacity
+    }
+    
+    // 根据 index，查找元素
+    func find(at index: Int) -> Element? {
+        // index 必须在 [0, count)
+        guard index >= 0, index < count else {
+            return nil
+        }
+        
+        return data[index]
+    }
+    
+    // 根据 index，删除元素
+    mutating func delete(at index: Int) -> Bool {
+        // index 必须在 [0, count)
+        guard index >= 0, index < count else {
+            return false
+        }
+        
+        // [index, count - 1) 从 index 开始，元素分别向前移动一位
+        for i in index ..< count - 1 {
+            data[i] = data[i+1]
+        }
+        count -= 1
+        return true
+    }
+    
+    // 根据 index 插入元素
+    mutating func insert(value: Element, at index: Int) -> Bool {
+        // index 必须在 [0, count)
+        guard index >= 0, index < count, count < capacity else {
+            return false
+        }
+        
+        // count - 1 ~ index
+        for i in (index ... count - 1).reversed() {
+            data[i + 1] = data[i]
+        }
+        
+        data[index] = value
+        count += 1
+        return true
+    }
+    
+    // 添加元素
+    mutating func add(value: Element) -> Bool {
+        guard count < capacity else {
+            return false
+        }
+        data[count] = value
+        count += 1
+        return true
+    }
+    
+    func printAll() {
+        print("\(data)")
+    }
+}
diff --git a/swift/09_queue/ArrayQueue.swift b/swift/09_queue/ArrayQueue.swift
new file mode 100644
index 0000000..1dea014
--- /dev/null
+++ b/swift/09_queue/ArrayQueue.swift
@@ -0,0 +1,112 @@
+//
+// Created by Jiandan on 2018/10/11.
+// Copyright (c) 2018 Jiandan. All rights reserved.
+//
+
+import Foundation
+
+/// 用数组实现的队列
+struct ArrayQueue<T>: Queue {
+    typealias Element = T
+    
+    /// 数组
+    private var items: [Element]
+    /// 数组最大长度
+    private var capacity = 0
+    /// 队头下标
+    private var head = 0
+    /// 队尾下标
+    private var tail = 0
+    
+    /// 构造方法
+    /// - parameter defaultElement: 默认元素
+    /// - parameter capacity: 数组长度
+    init(defaultElement: Element, capacity: Int) {
+        self.capacity = capacity
+        items = [Element](repeating: defaultElement, count: capacity)
+    }
+    
+    // MARK: Protocol: Queue
+    
+    var isEmpty: Bool { return head == tail }
+    
+    var size: Int { return tail - head }
+    
+    var peek: Element? { return isEmpty ? nil : items[head] }
+    
+    // 没有数据搬移的实现，即实现了一个有界序列
+//    mutating func enqueue(newElement: Element) -> Bool {
+//        // 整个队列都占满了
+//        if tail == capacity {
+//            return false
+//        }
+//
+//        items[tail] = newElement
+//        tail += 1
+//        return true
+//    }
+    // 有数据搬移的实现，即实现了一个无界序列
+    mutating func enqueue(newElement: Element) -> Bool {
+        // 如果 tail == capacity 表示队列末尾没有空间了
+        if tail == capacity {
+            // 整个队列都占满了
+            if head == 0 { return false }
+            // 数据搬移
+            for i in head ..< tail {
+                items[i - head] = items[i]
+            }
+            // 搬移完之后重新更新 head 和 tail
+            tail -= head
+            head = 0
+        }
+
+        items[tail] = newElement
+        tail += 1
+        return true
+    }
+    
+    mutating func dequeue() -> Element? {
+        if isEmpty {
+            return nil
+        }
+        
+        let item = items[head]
+        head += 1
+        return item
+    }
+}
+
+/// 使用2个数组实现无界队列，用到 Swift 中 Array 较多的方法
+/// 来源：《iOS 面试之道》（故胤道长，唐巧）
+struct ArrayQueue2<T>: Queue {
+    typealias Element = T
+    
+    /// 输入数组，主要负责入队
+    var inArray = [Element]()
+    /// 输出数组，主要负责出队
+    var outArray = [Element]()
+    
+    var isEmpty: Bool { return inArray.isEmpty && outArray.isEmpty }
+    
+    var size: Int { return inArray.count + outArray.count }
+    
+    // 当 outArray 为空时，返回 inArray 首个元素，否则返回 outArray 末尾元素
+    var peek: Element? { return outArray.isEmpty ? inArray.first : outArray.last }
+    
+    mutating func enqueue(newElement: Element) -> Bool {
+        // inArray 添加元素
+        inArray.append(newElement)
+        return true
+    }
+    
+    mutating func dequeue() -> Element? {
+        if outArray.isEmpty {
+            // 将 inArray 倒序存入 outArray 中
+            outArray = inArray.reversed()
+            // 清空 inArray
+            inArray.removeAll()
+        }
+        // 弹出 outArray 最后一个元素
+        return outArray.popLast()
+    }
+}
diff --git a/swift/09_queue/CircularQueue.swift b/swift/09_queue/CircularQueue.swift
new file mode 100644
index 0000000..6a58f98
--- /dev/null
+++ b/swift/09_queue/CircularQueue.swift
@@ -0,0 +1,63 @@
+//
+// Created by Jiandan on 2018/10/11.
+// Copyright (c) 2018 Jiandan. All rights reserved.
+//
+
+import Foundation
+
+/// 循环队列
+struct CircularQueue<T>: Queue {
+    typealias Element = T
+
+    /// 数组
+    private var items: [Element]
+    /// 数组最大长度
+    private var capacity = 0
+    /// 队头下标
+    private var head = 0
+    /// 队尾下标
+    private var tail = 0
+
+    /// 构造方法
+    /// - parameter defaultElement: 默认元素
+    /// - parameter capacity: 数组长度
+    init(defaultElement: Element, capacity: Int) {
+        self.capacity = capacity
+        items = [Element](repeating: defaultElement, count: capacity)
+    }
+
+    // MARK: Protocol: Queue
+
+    var isEmpty: Bool { return head == tail }
+
+    var size: Int {
+        if tail >= head {
+            return tail - head
+        } else {
+            return (tail + 1) + (capacity - head)
+        }
+    }
+
+    var peek: Element? { return isEmpty ? nil : items[head] }
+
+    mutating func enqueue(newElement: Element) -> Bool {
+        // 整个队列都占满了
+        if (tail + 1) % capacity == head {
+            return false
+        }
+
+        items[tail] = newElement
+        tail = (tail + 1) % capacity
+        return true
+    }
+
+    mutating func dequeue() -> Element? {
+        if isEmpty {
+            return nil
+        }
+
+        let item = items[head]
+        head = (head + 1) % capacity
+        return item
+    }
+}
diff --git a/swift/09_queue/Queue.swift b/swift/09_queue/Queue.swift
new file mode 100644
index 0000000..ab0bdd9
--- /dev/null
+++ b/swift/09_queue/Queue.swift
@@ -0,0 +1,21 @@
+//
+// Created by Jiandan on 2018/10/11.
+// Copyright (c) 2018 Jiandan. All rights reserved.
+//
+
+import Foundation
+
+protocol Queue {
+    /// 持有的数据类型
+    associatedtype Element
+    /// 是否为空
+    var isEmpty: Bool { get }
+    /// 队列大小
+    var size: Int { get }
+    /// 返回队列头部元素
+    var peek: Element? { get }
+    /// 入队
+    mutating func enqueue(newElement: Element) -> Bool
+    /// 出队
+    mutating func dequeue() -> Element?
+}
diff --git a/swift/09_queue/QueueBasedOnLinkedList.swift b/swift/09_queue/QueueBasedOnLinkedList.swift
new file mode 100644
index 0000000..be73795
--- /dev/null
+++ b/swift/09_queue/QueueBasedOnLinkedList.swift
@@ -0,0 +1,61 @@
+//
+// Created by Jiandan on 2018/10/11.
+// Copyright (c) 2018 Jiandan. All rights reserved.
+//
+
+import Foundation
+
+class Node<T> {
+    var value: T?
+    var next: Node?
+    
+    init(value: T) {
+        self.value = value
+    }
+}
+
+struct QueueBasedOnLinkedList<T>: Queue {
+    typealias Element = T
+    
+    /// 队首
+    var head: Node<Element>?
+    /// 队尾
+    var tail: Node<Element>?
+    
+    // MARK: Protocol: Queue
+    
+    var isEmpty: Bool { return head == nil }
+    
+    var size: Int {
+        var count = 0
+        while head?.next != nil {
+            count += 1
+        }
+        return count
+    }
+    
+    var peek: Element? { return head?.value }
+    
+    mutating func enqueue(newElement: Element) -> Bool {
+        if isEmpty {
+            // 空队列
+            let node = Node(value: newElement)
+            head = node
+            tail = node
+        } else {
+            tail!.next = Node(value: newElement)
+            tail = tail!.next
+        }
+        return true
+    }
+    
+    mutating func dequeue() -> Element? {
+        if isEmpty {
+            return nil
+        }
+        
+        let node = head
+        head = head!.next
+        return node?.value
+    }
+}