Merge branch 'master' of https://github.com/wangzheng0822/algo

2018-10-28 23:07:51 +08:00 · 2018-10-28 23:07:51 +08:00 · d4eba0b686
commit d4eba0b686
parent 4742ac4d53 c2e136f3d8
61 changed files with 2539 additions and 75 deletions
--- a/c-cpp/05_array/array.c
+++ b/c-cpp/05_array/array.c
@ -33,7 +33,7 @@ int insert(struct array *array, int elem)
 	}

 	if (idx < array->used)
-		memmove(&array->arr[array->used], &array->arr[idx],
+		memmove(&array->arr[idx+1], &array->arr[idx],
 			(array->used - idx) * sizeof(int));

 	array->arr[idx] = elem;
--- a/c-cpp/06_linkedlist/singlelist_gc/singleList.c
+++ b/c-cpp/06_linkedlist/singlelist_gc/singleList.c
@ -0,0 +1,281 @@
+#include "singleList.h"
+
+#include <string.h>
+
+linkedList * listCreate()
+{
+    linkedList *list = NULL;
+    list = malloc(sizeof(*list));
+    if (NULL == list)
+    {
+        return NULL;
+    }
+
+    list->dup = NULL;
+    list->free = NULL;
+    list->match = NULL;
+
+    list->head = NULL;
+    list->len = 0;
+
+    return list;
+}
+
+// 释放
+void listRelease(linkedList *list)
+{
+    if (NULL == list)
+    {
+        return;
+    }
+
+    listEmpty(list);
+
+    free(list);
+    list = NULL;
+}
+
+void listEmpty(linkedList *list)
+{
+    if (NULL == list)
+    {
+        return;
+    }
+
+    while (NULL != list->head)
+    {
+        listNode *pNode = list->head;
+        list->head = pNode->next;
+        if (NULL != list->free)
+        {
+            list->free(pNode->value);
+        }
+        else
+        {
+            free(pNode->value);
+        }
+
+        pNode->next = NULL;
+        free(pNode);
+        pNode = NULL;
+    }
+}
+
+linkedList * listAddNodeHead(linkedList *list, void * value)
+{
+    if (NULL == list || NULL == value)
+    {
+        return list;
+    }
+
+    listNode *node = NULL;
+    node = malloc(sizeof(*node));
+    if (NULL == node)
+    {
+        return list;
+    }
+
+    node->value = value;
+    node->next = list->head;
+    list->head = node;
+
+    ++list->len;
+    return list;
+}
+
+linkedList * listAddNodeTail(linkedList *list, void *value)
+{
+    if (NULL == list || NULL == value)
+    {
+        return list;
+    }
+
+    listNode *node = NULL;
+    node = malloc(sizeof(*node));
+    if (NULL == node)
+    {
+        return list;
+    }
+
+    node->value = value;
+    node->next = NULL;
+
+    if (NULL == list->head
+        && list->len == 0)
+    {
+        list->head = node;
+    }
+    else
+    {
+        listNode *tail = list->head;
+        listNode *pre = list->head;
+        while (NULL != tail)
+        {
+            pre = tail;
+            tail = tail->next;
+        }
+
+        pre->next = node;
+    }
+
+    ++list->len;
+    return list;
+}
+
+linkedList * listInsertNode(linkedList *list, listNode *old_node, void *value, bool after)
+{
+    if (NULL == list || NULL == old_node)
+    {
+        return list;
+    }
+
+    listNode *pNode = NULL;
+    pNode = malloc(sizeof(*pNode));
+    if (NULL == pNode)
+    {
+        return list;
+    }
+
+    pNode->value = value;
+    if (after)
+    {
+        pNode->next = old_node->next;
+        old_node->next = pNode;
+    }
+    else
+    {
+        listNode *pre = list->head;
+        while (pre->next != old_node)
+        {
+            pre = pre->next;
+        }
+
+        if (NULL != pre)
+        {
+            pre->next = pNode;
+            pNode->next = old_node;
+        }
+    }
+
+    ++list->len;
+    return list;
+}
+
+// 没设置释放函数时不做释放处理
+void listDelNode(linkedList *list, listNode *node)
+{
+    if (NULL == list || NULL == node)
+    {
+        return;
+    }
+
+    listNode *pre = list->head;
+    listNode *cur = list->head;
+    while (NULL != cur && cur != node)
+    {
+        pre = cur;
+        cur = cur->next;
+    }
+
+    // 不在该链表中
+    if (NULL == pre)
+    {
+        return;
+    }
+
+    pre->next = node->next;
+    node->next = NULL;
+    --list->len;
+
+    if (NULL != list->free)
+    {
+        list->free(node->value);
+        free(node);
+        node = NULL;
+    }
+}
+
+listNode * listSearchKey(linkedList *list, void *key)
+{
+    if (NULL == list)
+    {
+        return NULL;
+    }
+
+    listNode *node = list->head;
+    while (NULL != node)
+    {
+        if (NULL != list->match)
+        {
+            if (list->match(key, node->value) == 0)
+            {
+                return node;
+            }
+        }
+        else
+        {
+            if (key == node->value)
+            {
+                return node;
+            }
+        }
+
+        node = node->next;
+    }
+
+    return NULL;
+}
+
+listNode * listIndex(linkedList *list, long index)
+{
+    if (NULL == list)
+    {
+        return NULL;
+    }
+
+    if (index <= 0
+        || index > list->len)
+    {
+        return NULL;
+    }
+
+    listNode *pNode = list->head;
+    for (long i = 0; i < index; ++i)
+    {
+        pNode = pNode->next;
+    }
+
+    return pNode;
+}
+
+linkedList* listRewind(linkedList *list)
+{
+    if (NULL == list)
+    {
+        return NULL;
+    }
+
+    listNode *head = list->head;
+    listNode *pre = NULL;
+    listNode *next = NULL;
+    while (NULL != head)
+    {
+        next = head->next;
+        head->next = pre;
+        pre = head;
+        head = next;
+    }
+
+    list->head = pre;
+    return list;
+}
+
+size_t listLength(linkedList *list)
+{
+    if (NULL == list)
+    {
+        return 0;
+    }
+
+    return list->len;
+}
--- a/c-cpp/06_linkedlist/singlelist_gc/singleList.h
+++ b/c-cpp/06_linkedlist/singlelist_gc/singleList.h
@ -0,0 +1,46 @@
+#ifndef __SINGLELIST_H__
+#define __SINGLELIST_H__
+
+#include <stdlib.h>
+#include <stdbool.h>
+
+typedef struct listNode
+{
+    struct listNode *next;
+    void *value;
+}listNode;
+
+typedef struct linkedList
+{
+    listNode *head;
+    size_t len;
+    size_t typesize;
+
+    void(*dup)(void*, void*);
+    int(*match)(void*, void*);
+    void(*free)(void*);
+}linkedList;
+
+#define listSetDupMethod(l,m) ((l)->dup = (m))
+#define listSetFreeMethod(l,m) ((l)->free = (m))
+#define listSetMatchMethod(l,m) ((l)->match = (m))
+
+#define listGetDupMethod(l) ((l)->dup)
+#define listGetFree(l) ((l)->free)
+#define listGetMatchMethod(l) ((l)->match)
+
+linkedList *listCreate();
+void listRelease(linkedList *list);
+void listEmpty(linkedList *list);
+linkedList *listAddNodeHead(linkedList *list, void *value);
+linkedList *listAddNodeTail(linkedList *list, void *value);
+linkedList *listInsertNode(linkedList *list, listNode *old_node, void *value, bool after);
+void listDelNode(linkedList *list, listNode *node);
+
+listNode *listSearchKey(linkedList *list, void *key);
+listNode *listIndex(linkedList *list, long index);
+linkedList* listRewind(linkedList *list);
+
+size_t listLength(linkedList *list);
+
+#endif // !__SINGLELIST_H__
--- a/c-cpp/11_sorts/.gitkeep
+++ b/c-cpp/11_sorts/.gitkeep
--- a/c-cpp/11_sorts/sorts.c
+++ b/c-cpp/11_sorts/sorts.c
@ -0,0 +1,139 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+
+struct array {
+	int size;
+	int used;
+	int *arr;
+};
+
+void dump(struct array *array)
+{
+	int idx;
+	
+	for (idx = 0; idx < array->used; idx++)
+		printf("[%02d]: %08d\n", idx, array->arr[idx]);
+}
+
+void alloc(struct array *array)
+{
+	array->arr = (int *)malloc(array->size * sizeof(int));
+}
+
+void bubble_sort(struct array *array)
+{
+	int i, j;
+
+	if (array->used <= 1)
+		return;
+
+	for (i = 0; i < array->used; i++) {
+		bool has_swap = false;
+		for (j = 0; j < array->used - i - 1; j++) {
+			if (array->arr[j] > array->arr[j+1]) {
+				int tmp;
+				tmp = array->arr[j];
+				array->arr[j] = array->arr[j+1];
+				array->arr[j+1] = tmp;
+				has_swap = true;
+			}
+
+		}
+		if (!has_swap)
+			break;
+	}
+}
+
+void bubble_sort_test()
+{
+	int idx;
+	struct array ten_int = {10, 0, NULL};
+
+	alloc(&ten_int);
+	for (idx = 0; idx < 10; idx++)
+		ten_int.arr[idx] = 30 - idx;
+	ten_int.used = 10;
+	dump(&ten_int);
+	bubble_sort(&ten_int);
+	dump(&ten_int);
+}
+
+void insertion_sort(struct array *array)
+{
+	int i, j;
+
+	if (array->used <= 1)
+		return;
+
+	for (i = 1; i < array->used; i++) {
+		int val = array->arr[i];
+
+		for (j = i - 1; j >= 0; j--) {
+			if (val < array->arr[j])
+				array->arr[j+1] = array->arr[j]; 
+			else
+				break;
+		}
+		array->arr[j+1] = val;
+	}
+}
+
+void insertion_sort_test()
+{
+	int idx;
+	struct array ten_int = {10, 0, NULL};
+
+	alloc(&ten_int);
+	for (idx = 0; idx < 10; idx++)
+		ten_int.arr[idx] = 30 - idx;
+	ten_int.used = 10;
+	dump(&ten_int);
+	insertion_sort(&ten_int);
+	dump(&ten_int);
+}
+
+void selection_sort(struct array *array)
+{
+	int i, j;
+
+	if (array->used <= 1)
+		return;
+
+	for (i = 0; i < array->used - 1; i++) {
+		int tmp, idx = i;
+
+		for (j = i + 1; j < array->used; j++)
+			if (array->arr[j] < array->arr[idx])
+				idx = j;
+
+		if (idx == i)
+			continue;
+
+		tmp = array->arr[i];
+		array->arr[i] = array->arr[idx];
+		array->arr[idx] = tmp;
+	}
+}
+
+void selection_sort_test()
+{
+	int idx;
+	struct array ten_int = {10, 0, NULL};
+
+	alloc(&ten_int);
+	for (idx = 0; idx < 10; idx++)
+		ten_int.arr[idx] = 30 - idx;
+	ten_int.used = 10;
+	dump(&ten_int);
+	selection_sort(&ten_int);
+	dump(&ten_int);
+}
+
+int main()
+{
+	//bubble_sort_test();
+	//selection_sort_test();
+	insertion_sort_test();
+	return 0;
+}
--- a/c-cpp/11_sorts/sorts.cpp
+++ b/c-cpp/11_sorts/sorts.cpp
@ -0,0 +1,47 @@
+// C program for implementation of selection sort 
+#include <stdio.h> 
+
+void swap(int *xp, int *yp) 
+{ 
+	int temp = *xp; 
+	*xp = *yp; 
+	*yp = temp; 
+} 
+
+void selectionSort(int arr[], int n) 
+{ 
+	int i, j, min_idx; 
+
+	// One by one move boundary of unsorted subarray 
+	for (i = 0; i < n-1; i++) 
+	{ 
+		// Find the minimum element in unsorted array 
+		min_idx = i; 
+		for (j = i+1; j < n; j++) 
+		if (arr[j] < arr[min_idx]) 
+			min_idx = j; 
+
+		// Swap the found minimum element with the first element 
+		swap(&arr[min_idx], &arr[i]); 
+	} 
+} 
+
+/* Function to print an array */
+void printArray(int arr[], int size) 
+{ 
+	int i; 
+	for (i=0; i < size; i++) 
+		printf("%d ", arr[i]); 
+	printf("\n"); 
+} 
+
+// Driver program to test above functions 
+int main() 
+{ 
+	int arr[] = {64, 25, 12, 22, 11}; 
+	int n = sizeof(arr)/sizeof(arr[0]); 
+	selectionSort(arr, n); 
+	printf("Sorted array: \n"); 
+	printArray(arr, n); 
+	return 0; 
+} 
--- a/c-cpp/11_sorts/sorts.hpp
+++ b/c-cpp/11_sorts/sorts.hpp
@ -0,0 +1,89 @@
+/**
+ * Created by Liam Huang (Liam0205) on 2018/10/16.
+ */
+
+#ifndef SORTS_SORTS_HPP_
+#define SORTS_SORTS_HPP_
+
+#include <iterator>
+#include <functional>
+
+template <typename BidirIt,
+          typename BinaryPred = std::less<typename std::iterator_traits<BidirIt>::value_type>>
+void bubble_sort(BidirIt first, BidirIt last, BinaryPred comp = BinaryPred()) {
+    if (std::distance(first, last) <= 1) { return; }
+    bool flag = true;
+    for (auto it = first; flag and it != last; ++it) {
+        flag = false;
+        for (auto itt = first; itt != last - std::distance(first, it) - 1; ++itt) {
+            if (comp(*(itt + 1), *itt)) {
+                std::swap(*itt, *(itt + 1));
+                flag = true;
+            }
+        }
+    }
+}
+
+template <typename BidirIt,
+          typename BinaryPred = std::less<typename std::iterator_traits<BidirIt>::value_type>>
+void insertion_sort(BidirIt first, BidirIt last, BinaryPred comp = BinaryPred()) {
+    if (std::distance(first, last) <= 1) { return; }
+    for (auto it = first + 1; it != last; ++it) {
+        const auto target = *it;
+        auto       itt    = it;
+        for (; std::distance(first, itt) > 0 and comp(target, *(itt - 1)); --itt) {
+            *itt = *(itt - 1);
+        }
+        *itt = target;
+    }
+}
+
+template <typename BidirIt,
+          typename BinaryPred = std::less<typename std::iterator_traits<BidirIt>::value_type>>
+void selection_sort(BidirIt first, BidirIt last, BinaryPred comp = BinaryPred()) {
+    if (std::distance(first, last) <= 1) { return; }
+    for (auto it = first; it != last - 1; ++it) {
+        auto tag = it;
+        for (auto itt = it + 1; itt != last; ++itt) {
+            if (comp(*itt, *tag)) {
+                tag = itt;
+            }
+        }
+        if (tag != it) {
+            std::swap(*it, *tag);
+        }
+    }
+}
+
+template <typename FrwdIt,
+          typename BinaryPred = std::less<typename std::iterator_traits<FrwdIt>::value_type>>
+void bubble_down_sort(FrwdIt first, FrwdIt last, BinaryPred comp = BinaryPred()) {
+    if (std::distance(first, last) <= 1) { return; }
+    for (auto it = first; it != last; ++it) {
+        for (auto itt = it + 1; itt != last; ++itt) {
+            if (comp(*itt, *it)) {
+                std::swap(*it, *itt);
+            }
+        }
+    }
+}
+
+template <typename BidirIt,
+          typename BinaryPred = std::less<typename std::iterator_traits<BidirIt>::value_type>>
+void shell_sort(BidirIt first, BidirIt last, BinaryPred comp = BinaryPred()) {
+    const size_t len = std::distance(first, last);
+    if (len <= 1) { return; }
+    for (size_t step = len / 2; step >= 1; step /= 2) {
+        for (auto it = first + step; it != last; ++it) {
+            auto target = *it;
+            auto itt    = it - step;
+            for (; std::distance(first, itt) >= 0 and comp(target, *itt); itt -= step) {
+                *(itt + step) = *itt;
+            }
+            *(itt + step) = target;
+        }
+    }
+}
+
+#endif  // SORTS_SORTS_HPP_
+
--- a/c-cpp/11_sorts/sorts_test.cc
+++ b/c-cpp/11_sorts/sorts_test.cc
@ -0,0 +1,45 @@
+#include <iostream>
+#include <vector>
+
+#include "sorts.hpp"
+
+int main() {
+    const std::vector<int> test_data{1, 2, 3, 0};
+
+    std::vector<int> a(test_data.begin(), test_data.end());
+    bubble_sort(a.begin(), a.end());
+    for (auto i : a) {
+        std::cout << i << ' ';
+    }
+    std::cout << '\n';
+
+    std::vector<int> b(test_data.begin(), test_data.end());
+    insertion_sort(b.begin(), b.end());
+    for (auto i : b) {
+        std::cout << i << ' ';
+    }
+    std::cout << '\n';
+
+    std::vector<int> c(test_data.begin(), test_data.end());
+    selection_sort(c.begin(), c.end());
+    for (auto i : c) {
+        std::cout << i << ' ';
+    }
+    std::cout << '\n';
+
+    std::vector<int> d(test_data.begin(), test_data.end());
+    bubble_down_sort(d.begin(), d.end());
+    for (auto i : d) {
+        std::cout << i << ' ';
+    }
+    std::cout << '\n';
+
+    std::vector<int> e(test_data.begin(), test_data.end());
+    shell_sort(e.begin(), e.end());
+    for (auto i : e) {
+        std::cout << i << ' ';
+    }
+    std::cout << '\n';
+
+    return 0;
+}
--- a/c-cpp/12_sorts/.gitkeep
+++ b/c-cpp/12_sorts/.gitkeep
--- a/c-cpp/12_sorts/merge_sort.c
+++ b/c-cpp/12_sorts/merge_sort.c
@ -0,0 +1,84 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+
+void dump(int *arr, int size)
+{
+	int idx;
+
+	for (idx = 0; idx < size; idx++)
+		printf("%08d\n", arr[idx]);
+}
+
+void __merge(int *arr, int p, int q, int r)
+{
+	int *tmp;
+	int i, j, k;
+
+	tmp = (int*)malloc((r - p + 1) * sizeof(int));
+
+	if (!tmp)
+		abort();
+
+	for (i = p, j = q + 1, k = 0; i <= q && j <= r;) {
+		if (arr[i] <= arr[j])
+			tmp[k++] = arr[i++];
+		else
+			tmp[k++] = arr[j++];
+	}
+
+	if (i == q + 1) {
+		for (; j <= r;)
+			tmp[k++] = arr[j++];
+	} else {
+		for (; i <= q;)
+			tmp[k++] = arr[i++];
+	}
+
+	memcpy(arr + p, tmp, (r - p + 1) * sizeof(int));
+	free(tmp);
+}
+
+void __merge_sort(int *arr, int p, int r)
+{
+	int q;
+
+	if (p >= r)
+		return;
+
+	q = (p + r) / 2;
+	__merge_sort(arr, p, q);
+	__merge_sort(arr, q + 1, r);
+	__merge(arr, p, q, r);
+}
+
+void merge_sort(int *arr, int size)
+{
+	__merge_sort(arr, 0, size - 1);
+}
+
+void merge_verify()
+{
+	int test[10] = {5, 8, 9, 23, 67, 1, 3, 7, 31, 56};
+
+	__merge(test, 0, 4, 9);
+
+	dump(test, 10);
+}
+
+void merge_sort_test()
+{
+	int test[10] = {5, 8, 9, 23, 67, 1, 3, 7, 31, 56};
+
+	merge_sort(test, 10);
+
+	dump(test, 10);
+}
+
+int main()
+{
+	//merge_verify();
+	merge_sort_test();
+	return 0;
+}
--- a/c-cpp/12_sorts/merge_sort.hpp
+++ b/c-cpp/12_sorts/merge_sort.hpp
@ -0,0 +1,62 @@
+/**
+ * Created by Liam Huang (Liam0205) on 2018/10/17.
+ */
+
+#ifndef SORTS_MERGE_SORT_HPP_
+#define SORTS_MERGE_SORT_HPP_
+
+#include <functional>
+#include <algorithm>
+#include <iterator>
+#include <vector>
+
+namespace detail {
+template <typename InputIt1, typename InputIt2, typename OutputIt,
+          typename BinaryPred = std::less<typename std::iterator_traits<InputIt1>::value_type>>
+OutputIt merge(InputIt1 first1, InputIt1 last1,
+               InputIt2 first2, InputIt2 last2,
+               OutputIt d_first,
+               BinaryPred comp = BinaryPred()) {
+    for (; first1 != last1; ++d_first) {
+        if (first2 == last2) {
+            return std::copy(first1, last1, d_first);
+        }
+        if (comp(*first2, *first1)) {
+            *d_first = *first2;
+            ++first2;
+        } else {
+            *d_first = *first1;
+            ++first1;
+        }
+    }
+    return std::copy(first2, last2, d_first);
+}
+}  // namespace detail
+
+template <typename FrwdIt,
+          typename BinaryPred = std::less<typename std::iterator_traits<FrwdIt>::value_type>>
+void merge_sort(FrwdIt first, FrwdIt last, BinaryPred comp = BinaryPred()) {
+    const auto len = std::distance(first, last);
+    if (len <= 1) { return; }
+    auto cut = first + len / 2;
+    merge_sort(first, cut, comp);
+    merge_sort(cut, last, comp);
+    std::vector<typename std::iterator_traits<FrwdIt>::value_type> tmp;
+    tmp.reserve(len);
+    detail::merge(first, cut, cut, last, std::back_inserter(tmp), comp);
+    std::copy(tmp.begin(), tmp.end(), first);
+}
+
+template <typename BidirIt,
+          typename BinaryPred = std::less<typename std::iterator_traits<BidirIt>::value_type>>
+void inplace_merge_sort(BidirIt first, BidirIt last, BinaryPred comp = BinaryPred()) {
+    const auto len = std::distance(first, last);
+    if (len <= 1) { return; }
+    auto cut = first + len / 2;
+    inplace_merge_sort(first, cut, comp);
+    inplace_merge_sort(cut, last, comp);
+    std::inplace_merge(first, cut, last, comp);
+}
+
+#endif  // SORTS_MERGE_SORT_HPP_
+
--- a/c-cpp/12_sorts/merge_sort_test.cc
+++ b/c-cpp/12_sorts/merge_sort_test.cc
@ -0,0 +1,28 @@
+/**
+ * Created by Liam Huang (Liam0205) on 2018/10/17.
+ */
+
+#include <iostream>
+#include <vector>
+#include "merge_sort.hpp"
+
+int main() {
+    const std::vector<int> test_data{0, -1, 3, 190, -500};
+
+    std::vector<int> a{test_data};
+    merge_sort(a.begin(), a.end());
+    for (auto i : a) {
+        std::cout << i << ' ';
+    }
+    std::cout << std::endl;
+
+    std::vector<int> b{test_data};
+    inplace_merge_sort(b.begin(), b.end());
+    for (auto i : b) {
+        std::cout << i << ' ';
+    }
+    std::cout << std::endl;
+
+    return 0;
+}
+
--- a/c-cpp/12_sorts/quick_sort.c
+++ b/c-cpp/12_sorts/quick_sort.c
@ -0,0 +1,69 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+
+void dump(int *arr, int size)
+{
+	int idx;
+
+	for (idx = 0; idx < size; idx++)
+		printf("%08d\n", arr[idx]);
+}
+
+void swap(int *a, int *b)
+{
+	int tmp = *a;
+	*a = *b;
+	*b = tmp;
+}
+
+int partition(int *arr, int p, int r)
+{
+	//int pivot = arr[r];
+	int i, j;
+
+	i = j = p;
+
+	for (; j < r; j++) {
+		if (arr[j] < arr[r]) {
+			swap(arr + i, arr + j);
+			i++;
+		}
+	}
+	
+	swap(arr + i, arr + r);
+	return i;
+}
+
+void __quick_sort(int *arr, int p, int r)
+{
+	int q;
+
+	if (p >= r)
+		return;
+
+	q = partition(arr, p, r);
+	__quick_sort(arr, p, q-1);
+	__quick_sort(arr, q+1, r);
+}
+
+void quick_sort(int *arr, int size)
+{
+	__quick_sort(arr, 0, size - 1);
+}
+
+void quick_sort_test()
+{
+	int test[10] = {5, 8, 9, 23, 67, 1, 3, 7, 31, 56};
+
+	quick_sort(test, 10);
+
+	dump(test, 10);
+}
+
+int main()
+{
+	quick_sort_test();
+	return 0;
+}
--- a/c-cpp/12_sorts/quick_sort.hpp
+++ b/c-cpp/12_sorts/quick_sort.hpp
@ -0,0 +1,71 @@
+/**
+ * Created by Liam Huang (Liam0205) on 2018/10/17.
+ */
+
+#ifndef SORTS_QUICK_SORT_HPP_
+#define SORTS_QUICK_SORT_HPP_
+
+#include <functional>
+#include <iterator>
+#include <algorithm>
+#include <utility>
+
+namespace detail {
+template <typename T, typename Compare = std::less<T>>
+const T& median(const T& a, const T& b, const T& c, Compare comp = Compare()) {
+    if (comp(a, b) and comp(b, c) or comp(c, b) and comp(b, a)) {
+        return b;
+    } else if (comp(b, c) and comp(c, a) or comp(a, c) and comp(c, b)) {
+        return c;
+    } else {
+        return a;
+    }
+}
+
+template <typename Iter,
+          typename T = typename std::iterator_traits<Iter>::value_type,
+          typename Compare = std::less<T>>
+const T& iter_median(Iter a, Iter b, Iter c, Compare comp = Compare()) {
+    return median(*a, *b, *c, comp);
+}
+
+template <typename BidirIt,
+          typename T = typename std::iterator_traits<BidirIt>::value_type,
+          typename Compare = std::less<T>>
+std::pair<BidirIt, BidirIt> inplace_partition(BidirIt first,
+                                              BidirIt last,
+                                             const T& pivot,
+                                           Compare comp = Compare()) {
+    BidirIt last_less, last_greater, first_equal, last_equal;
+    for (last_less = first, last_greater = first, first_equal = last;
+                                         last_greater != first_equal; ) {
+        if (comp(*last_greater, pivot)) {
+            std::iter_swap(last_greater++, last_less++);
+        } else if (comp(pivot, *last_greater)) {
+            ++last_greater;
+        } else {  // pivot == *last_greater
+            std::iter_swap(last_greater, --first_equal);
+        }
+    }
+    const auto cnt = std::distance(first_equal, last);
+    std::swap_ranges(first_equal, last, last_less);
+    first_equal    = last_less;
+    last_equal     = first_equal + cnt;
+    return {first_equal, last_equal};
+}
+}  // namespace detail
+
+template <typename BidirIt,
+          typename T = typename std::iterator_traits<BidirIt>::value_type,
+          typename Compare = std::less<T>>
+void quick_sort(BidirIt first, BidirIt last, Compare comp = Compare()) {
+    for (auto size = std::distance(first, last); size > 1; size = std::distance(first, last)) {
+        const T pivot = detail::iter_median(first, last - 1, first + size / 2, comp);
+        const auto eq = detail::inplace_partition(first, last, pivot, comp);
+        quick_sort(first, eq.first, comp);
+        first = eq.second;  // Liam Huang: economize half of recursive calling.
+    }
+}
+
+#endif  // SORTS_QUICK_SORT_HPP_
+
--- a/c-cpp/12_sorts/quick_sort_test.cc
+++ b/c-cpp/12_sorts/quick_sort_test.cc
@ -0,0 +1,25 @@
+/**
+ * Created by Liam Huang (Liam0205) on 2018/10/17.
+ */
+
+#include <iostream>
+#include <vector>
+#include <algorithm>
+
+#include "quick_sort.hpp"
+
+void test_quick_sort(std::vector<int> test_data) {
+    quick_sort(test_data.begin(), test_data.end());
+    std::transform(test_data.begin(), test_data.end(),
+            std::ostream_iterator<int>(std::cout, " "), [](int i){ return i; });
+    std::cout << '\n';
+}
+
+int main() {
+    test_quick_sort({-3, -1, 1, -2, -3, 0, -3, 100, 1, 1, -100});
+    test_quick_sort({1, 1, 1});
+    test_quick_sort({1, 0, -1});
+    test_quick_sort({1});
+    return 0;
+}
+
--- a/c-cpp/14_sorts/.gitkeep
+++ b/c-cpp/14_sorts/.gitkeep
--- a/c-cpp/14_sorts/analytics_of_std_sort.md
+++ b/c-cpp/14_sorts/analytics_of_std_sort.md
@ -0,0 +1,8 @@
+# C++ STL 中的 std::sort 分析
+
+参见 [Liam Huang 的博客](https://liam.page/)中的 3 篇文章：
+
+* [谈谈基于比较的排序算法的复杂度下界](https://liam.page/2018/08/28/lower-bound-of-comparation-based-sort-algorithm/)
+* [谈谈内省式排序算法](https://liam.page/2018/08/29/introspective-sort/)
+* [谈谈 STL 中的 std::sort](https://liam.page/2018/09/18/std-sort-in-STL/)
+
--- a/c-cpp/14_sorts/counting_sort.c
+++ b/c-cpp/14_sorts/counting_sort.c
@ -0,0 +1,66 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+
+void dump(int *arr, int size)
+{
+	int i;
+
+	for (i = 0; i < size; i++)
+		printf("%08d\n", arr[i]);
+}
+
+// content in arr must be positive integer
+void counting_sort(int *arr, int size)
+{
+	int max, i;
+	int *count, *tmp;
+
+	if (size <= 1)
+		return;
+
+	max = 0;
+	// find the biggest integer
+	for (i = 0; i < size; i++) {
+		if (max < arr[i])
+			max = arr[i];
+	}
+
+	// init count to 0
+	count = (int*)malloc((max+1) * sizeof(int));
+	tmp = (int*)malloc(size * sizeof(int));
+	if (!count || !tmp)
+		return;
+	memset(count, 0, (max + 1) * sizeof(int));
+
+	// counting
+	for (i = 0; i < size; i++)
+		count[arr[i]]++;
+	for (i = 1; i < max + 1; i++)
+		count[i] = count[i-1] + count[i];
+
+	// iterate arr and put it to the correct index in tmp
+	for (i = 0; i < size; i++){
+		int index = count[arr[i]] - 1;
+		tmp[index] = arr[i];
+		count[arr[i]]--;
+	}
+
+	// move back to arr
+	memcpy(arr, tmp, size * sizeof(int));
+}
+
+void counting_sort_test()
+{
+	int test_data[10] = {3, 23, 98, 1, 27, 36, 52, 89, 76, 44};
+
+	counting_sort(test_data, 10);
+	dump(test_data, 10);
+}
+
+int main()
+{
+	counting_sort_test();
+	return 0;
+}
--- a/c-cpp/15_bsearch/.gitkeep
+++ b/c-cpp/15_bsearch/.gitkeep
--- a/c-cpp/15_bsearch/bsearch.hpp
+++ b/c-cpp/15_bsearch/bsearch.hpp
@ -0,0 +1,66 @@
+/**
+ * Created by Liam Huang (Liam0205) on 2018/10/24.
+ */
+
+#ifndef BSEARCH_BSEARCH_HPP_
+#define BSEARCH_BSEARCH_HPP_
+
+#include <iterator>
+#include <functional>
+
+enum class BsearchPolicy { FIRST, LAST, UNSPECIFIED };
+
+// Liam Huang: The algorithm works right with iterators that meet the ForwardIterator requirement,
+//             but with a bad time complexity. For better performance, iterators should meet
+//             the RandomAccessIterator requirement.
+template <typename IterT,
+          typename ValueT = typename std::iterator_traits<IterT>::value_type,
+          typename Compare>
+IterT bsearch(IterT first,
+              IterT last,
+             ValueT target,
+            Compare comp,
+      BsearchPolicy policy = BsearchPolicy::UNSPECIFIED) {
+    IterT result = last;
+    while (std::distance(first, last) > 0) {
+        IterT mid = first + std::distance(first, last) / 2;
+        if (comp(*mid, target)) {
+            first = mid + 1;
+        } else if (comp(target, *mid)) {
+            last = mid;
+        } else {  // equal
+            if (policy == BsearchPolicy::FIRST) {
+                if (mid == first or comp(*(mid - 1), *mid)) {
+                    result = mid;
+                    break;
+                } else {
+                    last = mid;
+                }
+            } else if (policy == BsearchPolicy::LAST) {
+                if (std::distance(mid, last) == 1 or comp(*mid, *(mid + 1))) {
+                    result = mid;
+                    break;
+                } else {
+                    first = mid + 1;
+                }
+            } else {
+                result = mid;
+                break;
+            }
+        }
+    }
+    return result;
+}
+
+template <typename IterT,
+          typename ValueT = typename std::iterator_traits<IterT>::value_type,
+          typename Compare = std::less<ValueT>>
+IterT bsearch(IterT first,
+              IterT last,
+             ValueT target,
+      BsearchPolicy policy = BsearchPolicy::UNSPECIFIED) {
+	return bsearch(first, last, target, Compare(), policy);
+}
+
+#endif  // BSEARCH_BSEARCH_HPP_
+
--- a/c-cpp/15_bsearch/bsearch_test.cc
+++ b/c-cpp/15_bsearch/bsearch_test.cc
@ -0,0 +1,38 @@
+/**
+ * Created by Liam Huang (Liam0205) on 2018/10/24.
+ */
+
+#include <iostream>
+#include <vector>
+
+#include "bsearch.hpp"
+
+template <typename VecT, typename T = typename VecT::value_type>
+void test_bsearch(const VecT& test,
+                            T target,
+                BsearchPolicy policy = BsearchPolicy::UNSPECIFIED) {
+    auto it = bsearch(test.begin(), test.end(), target, policy);
+    std::cout << std::distance(test.begin(), it) << std::endl;
+}
+
+int main() {
+    std::vector<int> test{0, 0, 1, 2, 3, 4, 4, 5, 5, 5, 5, 5, 6, 7};  // std::less<int>()
+
+    test_bsearch(test, 8);                        // 14
+    test_bsearch(test, -1);                       // 14
+    test_bsearch(test, 0);                        // 0, 1
+    test_bsearch(test, 0, BsearchPolicy::FIRST);  // 0
+    test_bsearch(test, 0, BsearchPolicy::LAST);   // 1
+    test_bsearch(test, 4);                        // 5, 6
+    test_bsearch(test, 4, BsearchPolicy::FIRST);  // 5
+    test_bsearch(test, 4, BsearchPolicy::LAST);   // 6
+    test_bsearch(test, 5);                        // 7, 8, 9, 10, 11
+    test_bsearch(test, 5, BsearchPolicy::FIRST);  // 7
+    test_bsearch(test, 5, BsearchPolicy::LAST);   // 11
+    test_bsearch(test, 7);                        // 13
+    test_bsearch(test, 7, BsearchPolicy::FIRST);  // 13
+    test_bsearch(test, 7, BsearchPolicy::LAST);   // 13
+
+    return 0;
+}
+
--- a/go/11_sorts/Sort.go
+++ b/go/11_sorts/Sort.go
@ -1,54 +1,66 @@
 package _1_sorts

-func BubbleSort(a []int) {
-	arrLen := len(a)
-	if arrLen <= 1 {
+/*
+冒泡排序、插入排序、选择排序
+ */
+
+//冒泡排序，a是数组，n表示数组大小
+func BubbleSort(a []int, n int) {
+	if n <= 1 {
 		return
 	}
-	for i := arrLen - 1; i > 0; i-- {
-		for j := 0; j < i; j++ {
+	for i := 0; i < n; i++ {
+		// 提前退出标志
+		flag := false
+		for j := 0; j < n-i-1; j++ {
 			if a[j] > a[j+1] {
-				tmp := a[j+1]
-				a[j+1] = a[j]
-				a[j] = tmp
+				a[j], a[j+1] = a[j+1], a[j]
+				//此次冒泡有数据交换
+				flag = true
 			}
 		}
+		// 如果没有交换数据，提前退出
+		if !flag {
+			break
+		}
 	}
 }

-func InsertSort(a []int) {
-	arrLen := len(a)
-	if arrLen <= 1 {
+// 插入排序，a表示数组，n表示数组大小
+func InsertionSort(a []int, n int) {
+	if n <= 1 {
 		return
 	}
-	for i := 1; i < arrLen; i++ {
-		v := a[i]
+	for i := 1; i < n; i++ {
+		value := a[i]
 		j := i - 1
+		//查找要插入的位置并移动数据
 		for ; j >= 0; j-- {
-			if a[j] > v {
+			if a[j] > value {
 				a[j+1] = a[j]
+			} else {
+				break
 			}
 		}
-		a[j+1] = v
+		a[j+1] = value
 	}
 }

-func SelectionSort(a []int) {
-	arrLen := len(a)
-	if arrLen <= 1 {
+// 选择排序，a表示数组，n表示数组大小
+func SelectionSort(a []int, n int) {
+	if n <= 1 {
 		return
 	}
-	for i := 0; i < arrLen; i++ {
+	for i := 0; i < n; i++ {
+		// 查找最小值
 		minIndex := i
-		for j := i + 1; j < arrLen; j++ {
+		for j := i + 1; j < n; j++ {
 			if a[j] < a[minIndex] {
 				minIndex = j
 			}
 		}
-		if minIndex != i {
-			tmp := a[minIndex]
-			a[minIndex] = a[i]
-			a[i] = tmp
-		}
+		// 交换
+		a[i], a[minIndex] = a[minIndex],a[i]
+
 	}
 }
--- a/go/11_sorts/Sort_test.go
+++ b/go/11_sorts/Sort_test.go
@ -1,43 +1,27 @@
 package _1_sorts

 import (
+	"fmt"
 	"testing"
 )

 func TestBubbleSort(t *testing.T) {
-	a := []int{5, 4, 3, 2, 1}
-	BubbleSort(a)
-	t.Log(a)
+	arr := []int{1,5,9,6,3,7,5,10}
+	fmt.Println("排序前：",arr)
+	BubbleSort(arr,len(arr))
+	fmt.Println("排序后：",arr)
+}
+
+func TestInsertionSort(t *testing.T) {
+	arr := []int{1,5,9,6,3,7,5,10}
+	fmt.Println("排序前：",arr)
+	InsertionSort(arr,len(arr))
+	fmt.Println("排序后：",arr)
 }

 func TestSelectionSort(t *testing.T) {
-	a := []int{5, 4, 3, 2, 1}
-	SelectionSort(a)
-	t.Log(a)
-}
-func TestInsertSort(t *testing.T) {
-	a := []int{5, 4, 3, 2, 1}
-	InsertSort(a)
-	t.Log(a)
-}
-
-func BenchmarkBubbleSort(b *testing.B) {
-	a := []int{5, 4, 3, 2, 1}
-	for i := 0; i < b.N; i++ {
-		BubbleSort(a)
-	}
-}
-
-func BenchmarkSelectionSort(b *testing.B) {
-	a := []int{5, 4, 3, 2, 1}
-	for i := 0; i < b.N; i++ {
-		SelectionSort(a)
-	}
-}
-
-func BenchmarkInsertSort(b *testing.B) {
-	a := []int{5, 4, 3, 2, 1}
-	for i := 0; i < b.N; i++ {
-		InsertSort(a)
-	}
+	arr := []int{1,5,9,6,3,7,5,10}
+	fmt.Println("排序前：",arr)
+	SelectionSort(arr,len(arr))
+	fmt.Println("排序后：",arr)
 }
--- a/go/12_sorts/MergeSort.go
+++ b/go/12_sorts/MergeSort.go
@ -0,0 +1,48 @@
+package _2_sorts
+
+func MergeSort(arr []int) {
+	arrLen := len(arr)
+	if arrLen <= 1 {
+		return
+	}
+
+	mergeSort(arr, 0, arrLen-1)
+}
+
+func mergeSort(arr []int, start, end int) {
+	if start >= end {
+		return
+	}
+
+	mid := (start + end) / 2
+	mergeSort(arr, start, mid)
+	mergeSort(arr, mid+1, end)
+	merge(arr, start, mid, end)
+}
+
+func merge(arr []int, start, mid, end int) {
+	tmpArr := make([]int, end-start+1)
+
+	i := start
+	j := mid + 1
+	k := 0
+	for ; i <= mid && j <= end; k++ {
+		if arr[i] < arr[j] {
+			tmpArr[k] = arr[i]
+			i++
+		} else {
+			tmpArr[k] = arr[j]
+			j++
+		}
+	}
+
+	for ; i <= mid; i++ {
+		tmpArr[k] = arr[i]
+		k++
+	}
+	for ; j <= end; j++ {
+		tmpArr[k] = arr[j]
+		k++
+	}
+	copy(arr[start:end+1], tmpArr)
+}
--- a/go/12_sorts/MergeSort_test.go
+++ b/go/12_sorts/MergeSort_test.go
@ -0,0 +1,13 @@
+package _2_sorts
+
+import "testing"
+
+func TestMergeSort(t *testing.T) {
+	arr := []int{5, 4}
+	MergeSort(arr)
+	t.Log(arr)
+
+	arr = []int{5, 4, 3, 2, 1}
+	MergeSort(arr)
+	t.Log(arr)
+}
--- a/go/12_sorts/QuickSort.go
+++ b/go/12_sorts/QuickSort.go
@ -0,0 +1,38 @@
+package _2_sorts
+
+func QuickSort(arr []int) {
+	arrLen := len(arr)
+	if arrLen <= 1 {
+		return
+	}
+	quickSort(arr, 0, arrLen-1)
+}
+
+func quickSort(arr []int, start, end int) {
+	if start >= end {
+		return
+	}
+
+	pivot := partition(arr, start, end)
+	quickSort(arr, start, pivot)
+	quickSort(arr, pivot+1, end)
+}
+
+func partition(arr []int, low, high int) int {
+	pivotV := arr[low]
+	for low < high {
+		for low < high && arr[high] > pivotV { //指针从右边开始向右找到一个比pivot小的数
+			high--
+		}
+		arr[low] = arr[high] //将这个数放到low位，注意第一次这个位置放的是pivot值，所以不会丢
+
+		for low < high && arr[low] < pivotV { //指针从左边开始向右找到第一个比pivot大的数
+			low++
+		}
+		arr[high] = arr[low] //将这个数赋值给之前的high指针，因为之前high指针指向的数已经被一定，所以不会丢
+	}
+
+	//最后将pivot的值放入合适位置，此时low与high相等
+	arr[low] = pivotV
+	return low
+}
--- a/go/12_sorts/QuickSort_test.go
+++ b/go/12_sorts/QuickSort_test.go
@ -0,0 +1,13 @@
+package _2_sorts
+
+import "testing"
+
+func TestQuickSort(t *testing.T) {
+	arr := []int{5, 4}
+	QuickSort(arr)
+	t.Log(arr)
+
+	arr = []int{5, 4, 3, 2, 1}
+	QuickSort(arr)
+	t.Log(arr)
+}
--- a/go/14_sorts/CountingSort.go
+++ b/go/14_sorts/CountingSort.go
@ -0,0 +1,33 @@
+package _4_sorts
+
+import "math"
+
+func CountingSort(a []int, n int) {
+	if n <= 1 {
+		return
+	}
+
+	var max int = math.MinInt32
+	for i := range a {
+		if a[i] > max {
+			max = a[i]
+		}
+	}
+
+	c := make([]int, max+1)
+	for i := range a {
+		c[a[i]]++
+	}
+	for i := 1; i <= max; i++ {
+		c[i] += c[i-1]
+	}
+
+	r := make([]int, n)
+	for i := range a {
+		index := c[a[i]] - 1
+		r[index] = a[i]
+		c[a[i]]--
+	}
+
+	copy(a, r)
+}
--- a/go/14_sorts/CountingSort_test.go
+++ b/go/14_sorts/CountingSort_test.go
@ -0,0 +1,13 @@
+package _4_sorts
+
+import "testing"
+
+func TestCountingSort(t *testing.T) {
+	arr := []int{5, 4}
+	CountingSort(arr, len(arr))
+	t.Log(arr)
+
+	arr = []int{5, 4, 3, 2, 1}
+	CountingSort(arr, len(arr))
+	t.Log(arr)
+}
--- a/go/15_binarysearch/binarysearch.go
+++ b/go/15_binarysearch/binarysearch.go
@ -0,0 +1,47 @@
+package _5_binarysearch
+
+func BinarySearch(a []int, v int) int {
+	n := len(a)
+	if n == 0 {
+		return -1
+	}
+
+	low := 0
+	high := n - 1
+	for low <= high {
+		mid := (low + high) / 2
+		if a[mid] == v {
+			return mid
+		} else if a[mid] > v {
+			high = mid - 1
+		} else {
+			low = mid + 1
+		}
+	}
+
+	return -1
+}
+
+func BinarySearchRecursive(a []int, v int) int {
+	n := len(a)
+	if n == 0 {
+		return -1
+	}
+
+	return bs(a, v, 0, n-1)
+}
+
+func bs(a []int, v int, low, high int) int {
+	if low > high {
+		return -1
+	}
+
+	mid := (low + high) / 2
+	if a[mid] == v {
+		return mid
+	} else if a[mid] > v {
+		return bs(a, v, low, mid-1)
+	} else {
+		return bs(a, v, mid+1, high)
+	}
+}
--- a/go/15_binarysearch/binarysearch_test.go
+++ b/go/15_binarysearch/binarysearch_test.go
@ -0,0 +1,27 @@
+package _5_binarysearch
+
+import "testing"
+
+func TestBinarySearch(t *testing.T) {
+	var a []int
+
+	a = []int{1, 3, 5, 6, 8}
+	if BinarySearch(a, 8) != 4 {
+		t.Fatal(BinarySearch(a, 3))
+	}
+	if BinarySearch(a, 4) != -1 {
+		t.Fatal(BinarySearch(a, 4))
+	}
+}
+
+func TestBinarySearchRecursive(t *testing.T) {
+	var a []int
+
+	a = []int{1, 3, 5, 6, 8}
+	if BinarySearchRecursive(a, 8) != 4 {
+		t.Fatal(BinarySearch(a, 3))
+	}
+	if BinarySearchRecursive(a, 4) != -1 {
+		t.Fatal(BinarySearch(a, 4))
+	}
+}
--- a/java/05_array/GenericArray.java
+++ b/java/05_array/GenericArray.java
@ -1,21 +1,21 @@
 /**
- * 
+ *
 * 1）泛型动态数组
 *
- * Author: shi
+ * Author: shi
 */

 public class GenericArray<T> {
     private T[] data;
     private int size;

-     // 根据传入容量，构造Array
+     // 根据传入容量，构造Array
     public GenericArray(int capacity) {
         data = (T[]) new Object[capacity];
         size = 0;
     }

-     // 无参构造方法，默认数组容量为10
+     // 无参构造方法，默认数组容量为10
     public GenericArray() {
         this(10);
     }
@ -57,7 +57,7 @@
         return false;
     }

-     // 获取对应元素的下标, 未找到，返回 -1 
+     // 获取对应元素的下标, 未找到，返回 -1
     public int find(T e) {
         for ( int i = 0; i < size; i++) {
             if (data[i].equals(e)) {
@ -66,12 +66,12 @@
         }
         return -1;
     }
-     
+

     // 在 index 位置，插入元素e, 时间复杂度 O(m+n)
     public void add(int index, T e) {
         checkIndex(index);
-         // 如果当前元素个数等于数组容量，则将数组扩容为原来的2倍
+         // 如果当前元素个数等于数组容量，则将数组扩容为原来的2倍
         if (size == data.length) {
             resize(2 * data.length);
         }
@ -96,7 +96,7 @@
     // 删除 index 位置的元素，并返回
     public T remove(int index) {
         checkIndex(index);
-         
+
         T ret = data[index];
         for (int i = index + 1; i < size; i++) {
             data[i - 1] = data[i];
@ -158,7 +158,7 @@

     private void checkIndex(int index) {
        if (index < 0 || index > size) {
-            throw new IllegalArgumentException("Add failed! Require index >=0 and index <= size.");
+            throw new IllegalArgumentException("Add failed! Require index >=0 and index <= size.");
        }
     }
 }
--- a/java/11_sorts/Sorts.java
+++ b/java/11_sorts/Sorts.java
@ -49,15 +49,31 @@ public class Sorts {
  // 选择排序，a表示数组，n表示数组大小
  public static void selectionSort(int[] a, int n) {
    if (n <= 1) return;
+<<<<<<< HEAD
+    for (int i = 0; i < n; ++i) {
+      // 查找最小值
+      int minIndex = i;
+      int minValue = a[i];
+      for (int j = i; j < n; ++j) {
+        if (a[j] < minValue) {
+          minValue = a[j];
+=======
    for (int i = 0; i < n - 1; ++i) {
      // 查找最小值
      int minIndex = i;
      for (int j = i + 1; j < n; ++j) {
        if (a[j] < a[minIndex]) {
+>>>>>>> upstream/master
          minIndex = j;
        }
      }

+<<<<<<< HEAD
+=======
+      if (minIndex == i)
+        continue;
+
+>>>>>>> upstream/master
      // 交换
      int tmp = a[i];
      a[i] = a[minIndex];
--- a/java/12_sorts/MergeSort.java
+++ b/java/12_sorts/MergeSort.java
@ -15,8 +15,8 @@ public class MergeSort {
    // 递归终止条件
    if (p >= r) return;

-    // 取p到r之间的中间位置q
-    int q = (p+r)/2;
+    // 取p到r之间的中间位置q,防止（p+r）的和超过int类型最大值
+    int q = p + (r - p)/2;
    // 分治递归
    mergeSortInternally(a, p, q);
    mergeSortInternally(a, q+1, r);
--- a/java/13_sorts/CountingSort.java
+++ b/java/13_sorts/CountingSort.java
--- a/javascript/05_array/Array.md
+++ b/javascript/05_array/Array.md
@ -282,7 +282,7 @@ Point 2: 2, 4
 Point 3: 8, 1
 Point 4: 2, 9

-也可以用之前的 puh() 等操作方法来操作对象数组
+也可以用之前的 push() 等操作方法来操作对象数组
 ```
 var p5 = new Point(11,13);
 point.push(p5);
--- a/javascript/11_sorts/sort.js
+++ b/javascript/11_sorts/sort.js
@ -0,0 +1,68 @@
+/**
+ * 冒泡，插入，选择排序
+ *
+ * Author: nameczz
+ */
+
+// 冒泡排序
+const bubbleSort = (arr) => {
+    if (arr.length <= 1) return
+    for (let i = 0; i < arr.length; i++) {
+        let hasChange = false
+        for (let j = 0; j < arr.length - i - 1; j++) {
+            if (arr[j] > arr[j + 1]) {
+                const temp = arr[j]
+                arr[j] = arr[j + 1]
+                arr[j + 1] = temp
+                hasChange = true
+            }
+        }
+        // 如果false 说明所有元素已经到位
+        if (!hasChange) break
+    }
+    console.log(arr)
+}
+
+// 插入排序
+const insertionSort = (arr) => {
+    if (arr.length <= 1) return
+    for (let i = 1; i < arr.length; i++) {
+        const temp = arr[i]
+        let j = i - 1
+        // 若arr[i]前有大于arr[i]的值的化，向后移位，腾出空间，直到一个<=arr[i]的值
+        for (j; j >= 0; j--) {
+            if (arr[j] > temp) {
+                arr[j + 1] = arr[j]
+            } else {
+                break
+            }
+        }
+        arr[j + 1] = temp
+    }
+    console.log(arr)
+}
+
+// 选择排序
+const selectionSort = (arr) => {
+    if (arr.length <= 1) return
+    // 需要注意这里的边界, 因为需要在内层进行 i+1后的循环，所以外层需要 数组长度-1
+    for (let i = 0; i < arr.length - 1; i++) {
+        let minIndex = i
+        for (let j = i + 1; j < arr.length; j++) {
+            if (arr[j] < arr[minIndex]) {
+                minIndex = j // 找到整个数组的最小值
+            }
+        }
+        const temp = arr[i]
+        arr[i] = arr[minIndex]
+        arr[minIndex] = temp
+    }
+    console.log(arr)
+}
+
+const test = [4, 5, 6, 3, 2, 1]
+bubbleSort(test)
+const testSort = [4, 1, 6, 3, 2, 1]
+insertionSort(testSort)
+const testSelect = [4, 8, 6, 3, 2, 1, 0, 12]
+selectionSort(testSelect)
--- a/javascript/12_sorts/MergeSort.js
+++ b/javascript/12_sorts/MergeSort.js
@ -0,0 +1,43 @@
+/**
+ * 归并排序
+ *
+ * Author: nameczz
+ */
+
+const mergeArr = (left, right) => {
+    let temp = []
+    let leftIndex = 0
+    let rightIndex = 0
+    // 判断2个数组中元素大小，依次插入数组
+    while (left.length > leftIndex && right.length > rightIndex) {
+        if (left[leftIndex] <= right[rightIndex]) {
+            temp.push(left[leftIndex])
+            leftIndex++
+        } else {
+            temp.push(right[rightIndex])
+            rightIndex++
+        }
+    }
+    // 合并 多余数组
+    return temp.concat(left.slice(leftIndex)).concat(right.slice(rightIndex))
+}
+
+const mergeSort = (arr) => {
+    // 当任意数组分解到只有一个时返回。
+    if (arr.length <= 1) return arr
+    const middle = Math.floor(arr.length / 2) // 找到中间值
+    const left = arr.slice(0, middle) // 分割数组
+    const right = arr.slice(middle)
+    // 递归 分解 合并
+    return mergeArr(mergeSort(left), mergeSort(right))
+}
+
+const testArr = []
+let i = 0
+while (i < 100) {
+    testArr.push(Math.floor(Math.random() * 1000))
+    i++
+}
+
+const res = mergeSort(testArr)
+console.log(res)
--- a/javascript/12_sorts/QuickSort.js
+++ b/javascript/12_sorts/QuickSort.js
@ -0,0 +1,46 @@
+/**
+ * 快速排序
+ *
+ * Author: nameczz
+ */
+
+const swap = (arr, i, j) => {
+    const temp = arr[i]
+    arr[i] = arr[j]
+    arr[j] = temp
+}
+
+// 获取 pivot 交换完后的index
+const partition = (arr, pivot, left, right) => {
+    const pivotVal = arr[pivot]
+    let startIndex = left
+    for (let i = left; i < right; i++) {
+        if (arr[i] < pivotVal) {
+            swap(arr, i, startIndex)
+            startIndex++
+        }
+    }
+    swap(arr, startIndex, pivot)
+    return startIndex
+}
+
+const quickSort = (arr, left, right) => {
+    if (left < right) {
+        let pivot = right
+        let partitionIndex = partition(arr, pivot, left, right)
+        quickSort(arr, left, partitionIndex - 1 < left ? left : partitionIndex - 1)
+        quickSort(arr, partitionIndex + 1 > right ? right : partitionIndex + 1, right)
+    }
+
+}
+
+
+const testArr = []
+let i = 0
+while (i < 10) {
+    testArr.push(Math.floor(Math.random() * 1000))
+    i++
+}
+console.log('unsort', testArr)
+quickSort(testArr, 0, testArr.length - 1);
+console.log('sort', testArr)
--- a/notes/11_sorts/readme.md
+++ b/notes/11_sorts/readme.md
@ -0,0 +1,100 @@
+# 排序（上）
+
+| 排序算法 | 时间复杂度 | 是否基于比较 |
+|---------|----|----|
+| 冒泡、插入、选择 | $O(n^2)$ | [y] |
+| 快排、归并 | $O(n\log n)$ | [y] |
+| 桶、基数、计数 | $O(n) | [x] |
+
+开篇问题：插入排序和冒泡排序的时间复杂度相同，都是 $O(n^2)$，在实际软件开发中，为什么我们更倾向于使用插入排序而不是冒泡排序？
+
+## 如何分析「排序算法」？
+
+### 算法执行效率
+
+1. 最好、最坏、平均情况的时间复杂度
+2. 时间复杂度的系数、低阶、常数——在渐进复杂度相同的情况下，需要比较系数、低阶和常数
+3. 比较和交换（移动）的次数——基于比较的排序算法的两种基本操作
+
+### 算法的内存消耗
+
+是否为原地排序算法（In-place sort algorithm），即算法的空间复杂度是否为 $O(1)$。
+
+### 排序的稳定性
+
+经过排序算法处理后，值相同的元素，在原序列和排序后序列中的相对位置保持不变，则称该排序算法是稳定的。
+
+> 待排序的 `item` 并不是简单的值，而是一个基于对象中的某个 `key` 进行排序时，排序的稳定性就有意义了。
+
+## 冒泡排序
+
+* 每次循环都从序列起始位置开始
+* 循环中的每个动作，都对比相邻两个元素的大小是否满足偏序要求，若不满足，则交换顺序
+
+![冒泡排序例图](https://static001.geekbang.org/resource/image/88/34/8890cbf63ea80455ce82490a23361134.jpg)
+
+分析：
+
+* 原地排序
+* 稳定排序（偏序关系是严格的偏序关系，如 `<` 或 `>`）
+* 时间复杂度
+  * 最好 $O(n)$
+  * 最坏 $O(n^2)$
+  * 平均 $O(n^2)$
+
+### 冒泡排序的平均时间复杂度非严格分析
+
+* 有序度：序列中满足偏序关系的两两组合的元素对的个数
+* 满有序度：排序完成的序列的有序度，它等于 $n(n - 1) / 2$
+* 逆序度：序列中不满足偏序关系的亮亮组合的元素对的个数
+
+显然，$\text{逆序度} = \text{满有序度} - \text{有序度}$。
+
+在冒泡排序中，每产生一次「交换」操作，$\text{逆序度}--$。于是，平均情况下，需要 $n(n - 1)/4$ 次交换操作，它已经是 $O(n^2)$ 了。因此，尽管比较操作的数量会大于交换操作的数量，但我们依然能说，冒泡排序的平均时间复杂度是 $O(n^2)$。
+
+> 分析过程不严格，但足够说明问题。
+
+## 插入排序
+
+1. 将待排序数列分为已排序区间和未排序区间
+2. 取未排序区间的第一个元素
+3. 遍历已排序区间，按照偏序关系，寻找合适的位置，插入未排序区间的第一个元素
+4. 重复 2 -- 3 直至未排序区间长度为零
+
+![插入排序例图](https://static001.geekbang.org/resource/image/fd/01/fd6582d5e5927173ee35d7cc74d9c401.jpg)
+
+分析：
+
+* 原地排序
+* 稳定排序（值相同的元素，往后插）
+* 时间复杂度
+  * 最好 $O(n)$
+  * 最坏 $O(n^2)$
+  * 平均 $O(n^2)$（乘法法则）
+
+## 选择排序
+
+1. 将待排序数列分为已排序区间和未排序区间
+2. 遍历未排序区间，取未排序区间的最小元素
+3. 交换上述最小元素与未排序区间中的第一个元素的位置
+4. 重复 2 -- 3 直至未排序区间长度为零
+
+![选择排序例图](https://static001.geekbang.org/resource/image/32/1d/32371475a0b08f0db9861d102474181d.jpg)
+
+分析：
+
+* 非原地排序
+* 非稳定排序
+* 时间复杂度
+  * 最好 $O(n^2)$
+  * 最坏 $O(n^2)$
+  * 平均 $O(n^2)$（乘法法则）
+
+## 开篇问题
+
+* 对同一份未排序序列数据，冒泡排序和插入排序所需的交换（移动）次数是一定的，且是相等的
+* 单次数据交换，冒泡排序所需的时间更长（三次赋值操作，插排只需要一次）
+
+另有插入排序的优化版本[希尔排序](https://zh.wikipedia.org/wiki/%E5%B8%8C%E5%B0%94%E6%8E%92%E5%BA%8F)。
+
+![小结](https://static001.geekbang.org/resource/image/34/50/348604caaf0a1b1d7fee0512822f0e50.jpg)
--- a/php/08_stack/Compute.php
+++ b/php/08_stack/Compute.php
@ -28,6 +28,8 @@ function expression($str)
                array_push($operStack, $arr[$i]);
                break;
            case '*':
+<<<<<<< HEAD
+=======
                $arrLen = count($operStack);
                while ($operStack[$arrLen-1] === '/'){
                    compute($numStack, $operStack);
@ -36,6 +38,7 @@ function expression($str)
                array_push($operStack, $arr[$i]);
                break;

+>>>>>>> upstream/master
            case '/':
            case '(':
                array_push($operStack, $arr[$i]);
@ -78,9 +81,13 @@ function compute(&$numStack, &$operStack){
        case '-':
            array_push($numStack, array_pop($numStack) - $num);
            break;
+<<<<<<< HEAD
+        
+=======
        case '(':
            throw new \Exception("不匹配的(", 2);
            break;
+>>>>>>> upstream/master
    }
 }
 expression('-1+2-(1+2*3)');
--- a/php/12_sort/mergeSort.php
+++ b/php/12_sort/mergeSort.php
@ -0,0 +1,66 @@
+<?php
+
+    $arr = [4, 5, 6, 1, 3, 2];
+    $length = count($arr);
+
+    $p = 0;
+    $r = $length - 1;
+
+    $result = $this->mergeSort($arr, $p, $r);
+
+    var_dump($result);
+
+
+//递归调用,分解数组
+function mergeSort(array $arr, $p, $r)
+{
+    if ($p >= $r) {
+        return [$arr[$r]];
+    }
+    $q = (int)(($p + $r) / 2);
+
+    $left = $this->mergeSort($arr, $p, $q);
+    $right = $this->mergeSort($arr, $q + 1, $r);
+    return $this->merge($left, $right);
+}
+
+//合并
+function merge(array $left, array $right)
+{
+    $tmp = [];
+
+    $i = 0;
+
+    $j = 0;
+
+    $leftLength = count($left);
+
+    $rightLength = count($right);
+
+    do {
+        if ($left[$i] <= $right[$j]) {
+            $tmp[] = $left[$i++];
+        } else {
+            $tmp[] = $right[$j++];
+        }
+
+    } while ($i < $leftLength && $j < $rightLength);
+
+
+    $start = $i;
+    $end = $leftLength;
+    $copyArr = $left;
+
+    if ($j < $rightLength) {
+        $start = $j;
+        $end = $rightLength;
+        $copyArr = $right;
+    }
+
+    for (; $start < $end; $start++) {
+        $tmp[] = $copyArr[$start];
+    }
+
+    return $tmp;
+
+}
--- a/php/README.md
+++ b/php/README.md
@ -17,7 +17,11 @@
 * findMiddleNode 求链表的中间结点

 #### 08_stack
+<<<<<<< HEAD
+* 链栈实现
+=======
 * 链栈实现

 #### 09_stack
-* 队列链表实现
+* 队列链表实现
+>>>>>>> upstream/master
--- a/php/Stack/Compute.php
+++ 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);');
--- a/php/composer.json
+++ b/php/composer.json
@ -7,8 +7,12 @@
        "psr-4": {
            "Algo_06\\": "06_linkedlist/",
            "Algo_07\\": "07_linkedlist/",
+<<<<<<< HEAD
+            "Algo_08\\": "08_stack/"
+=======
            "Algo_08\\": "08_stack/",
            "Algo_09\\": "09_queue/"
+>>>>>>> upstream/master
        }
    }
 }
--- a/python/05_array/myarray.py
+++ b/python/05_array/myarray.py
@ -9,35 +9,53 @@ class MyArray:
    """A simple wrapper around List.
    You cannot have -1 in the array.
    """
+
    def __init__(self, capacity: int):
+
        self._data = []
        self._count = 0
        self._capacity = capacity
    
    def __getitem__(self, position: int) -> int:
+
        """Support for subscript.
        Perhaps better than the find() method below.
        """
        return self._data[position]

    def find(self, index: int) -> Optional[int]:
+
        if index >= self._count or index <= -self._count: return None
        return self._data[index]

    def delete(self, index: int) -> bool:
+        
        if index >= self._count or index <= -self._count: return False
+        
        self._data[index:-1] = self._data[index+1:]
        self._count -= 1
+        # 真正将数据删除并覆盖原来的数据 ，这个需要增加
+        self._data = self._data[0:self._count]
+        print ('delet function',self._data)
        return True

    def insert(self, index: int, value: int) -> bool:
-        if index >= self._count or index <= -self._count: return False
+
+        #if index >= self._count or index <= -self._count: return False
        if self._capacity == self._count: return False
-        self._data.insert(index, value)
+        # 如果还有空间，那么插入位置大于当前的元素个数，可以插入最后的位置
+        if index >= self._count:
+            self._data.append(value)
+        # 同上，如果位置小于0 可以插入第０个位置.
+        if index < 0:
+            print (index)
+            self._data.insert(0, value)
+
        self._count += 1
        return True

    def insert_to_tail(self, value: int) -> bool:
+
        if self._count == self._capacity: return False
        if self._count == len(self._data):
            self._data.append(value) 
@ -47,11 +65,13 @@ class MyArray:
        return True
    
    def __repr__(self) -> str:
+
        return " ".join(str(num) for num in self._data[:self._count])

    def print_all(self):
+
        for num in self._data[:self._count]:
-            print(f"{num}", end=" ")
+            print("{num}", end=" ")
        print("\n", flush=True)

 if __name__ == "__main__":
@ -59,7 +79,17 @@ if __name__ == "__main__":
    for i in range(6):
        a.insert_to_tail(i)
    
+<<<<<<< HEAD
    a.delete(2)
    print(a)
    a.insert_to_tail(7)
-    print(a)
+    print(a)
+=======
+    print('origin',a)
+    a.delete(4)
+    print ('delete ',a)
+
+    a.insert(100,10000)
+    print (a)
+
+>>>>>>> upstream/master
--- a/python/06_linkedlist/palindrome.py
+++ b/python/06_linkedlist/palindrome.py
@ -0,0 +1,54 @@
+"""
+    check a single-linked list whether a palindrome
+"""
+
+import sys
+# 引用当前文件夹下的single_linked_list
+sys.path.append('singly_linked_list')
+from singly_linked_list import SinglyLinkedList
+
+def reverse(head):
+    reverse_head = None
+    while head:
+        next = head._next
+        head._next = reverse_head
+        reverse_head = head
+        head = next
+
+    return reverse_head
+
+def is_palindrome(l):
+    l.print_all()
+    slow = l._head
+    fast = l._head
+    position = 0
+    while fast and fast._next:
+        slow = slow._next
+        fast = fast._next._next
+        position += 1
+
+    reverse_node = reverse(slow)
+    head_node = l._head
+    is_palin = True
+    while (head_node and reverse_node):
+        if (head_node.data == reverse_node.data):
+            head_node = head_node._next
+            reverse_node = reverse_node._next
+        else:
+            is_palin = False
+            break
+
+    return is_palin
+
+if __name__ == '__main__':
+    # the result should be False, True, True, True, True
+    test_str_arr = ['ab', 'aa', 'aba', 'abba', 'abcba']
+    for str in test_str_arr:
+        l = SinglyLinkedList()
+        for i in str:
+            l.insert_value_to_head(i)
+
+        print(is_palindrome(l))
+
+
+
--- a/python/09_queue/array_queue.py
+++ b/python/09_queue/array_queue.py
@ -21,7 +21,11 @@ class ArrayQueue:
                return False
            else:
                for i in range(0, self._tail - self._head):
+<<<<<<< HEAD
                    self._data[i] = self._items[i + self._head]
+=======
+                    self._items[i] = self._items[i + self._head]
+>>>>>>> upstream/master
                self._tail = self._tail - self._head
                self._head = 0
        
--- a/python/11_sorts/sorts.py
+++ b/python/11_sorts/sorts.py
@ -11,8 +11,13 @@ from typing import List
 def bubble_sort(a: List[int]):
    if len(a) <= 1: return
    
+<<<<<<< HEAD
    made_swap = False
    for i in range(len(a)):
+=======
+    for i in range(len(a)):
+        made_swap = False
+>>>>>>> upstream/master
        for j in range(len(a) - i - 1):
            if a[j] > a[j+1]:
                a[j], a[j+1] = a[j+1], a[j]
--- a/python/12_sorts/merge_sort.py
+++ b/python/12_sorts/merge_sort.py
@ -0,0 +1,48 @@
+"""
+    Author: Wenru
+"""
+
+from typing import List
+
+def merge_sort(a: List[int]):
+    _merge_sort_between(a, 0, len(a)-1)
+
+def _merge_sort_between(a: List[int], low: int, high: int):
+    # The indices are inclusive for both low and high.
+    if low >= high: return
+    mid = low + (high - low)//2
+    _merge_sort_between(a, low, mid)
+    _merge_sort_between(a, mid+1, high)
+
+    _merge(a, low, mid, high)
+
+def _merge(a: List[int], low: int, mid: int, high: int):
+    # a[low:mid], a[mid+1, high] are sorted.
+    i, j = low, mid+1
+    tmp = []
+    while i <= mid and j <= high:
+        if a[i] <= a[j]:
+            tmp.append(a[i])
+            i += 1
+        else:
+            tmp.append(a[j])
+            j += 1
+    start = i if i <= mid else j
+    end = mid if i <= mid else high
+    tmp.extend(a[start:end+1])
+    a[low:high+1] = tmp
+
+
+if __name__ == "__main__":
+    a1 = [3, 5, 6, 7, 8]
+    a2 = [2, 2, 2, 2]
+    a3 = [4, 3, 2, 1]
+    a4 = [5, -1, 9, 3, 7, 8, 3, -2, 9]
+    merge_sort(a1)
+    print(a1)
+    merge_sort(a2)
+    print(a2)
+    merge_sort(a3)
+    print(a3)
+    merge_sort(a4)
+    print(a4)
--- a/python/12_sorts/quick_sort.py
+++ b/python/12_sorts/quick_sort.py
@ -0,0 +1,43 @@
+"""
+    Author: Wenru
+"""
+
+from typing import List
+import random
+
+def quick_sort(a: List[int]):
+    _quick_sort_between(a, 0, len(a)-1)
+
+def _quick_sort_between(a: List[int], low: int, high: int):
+    if low >= high: return
+    # get a random position as the pivot
+    k = random.randint(low, high)
+    a[low], a[k] = a[k], a[low]
+
+    m = _partition(a, low, high)   # a[m] is in final position
+    _quick_sort_between(a, low, m-1)
+    _quick_sort_between(a, m+1, high)
+
+def _partition(a: List[int], low: int, high: int):
+    pivot, j = a[low], low
+    for i in range(low+1, high+1):
+        if a[i] <= pivot:
+            j += 1
+            a[j], a[i] = a[i], a[j]  # swap
+    a[low], a[j] = a[j], a[low]
+    return j
+
+
+if __name__ == "__main__":
+    a1 = [3, 5, 6, 7, 8]
+    a2 = [2, 2, 2, 2]
+    a3 = [4, 3, 2, 1]
+    a4 = [5, -1, 9, 3, 7, 8, 3, -2, 9]
+    quick_sort(a1)
+    print(a1)
+    quick_sort(a2)
+    print(a2)
+    quick_sort(a3)
+    print(a3)
+    quick_sort(a4)
+    print(a4)
--- a/python/14_sorts/counting_sort.py
+++ b/python/14_sorts/counting_sort.py
@ -0,0 +1,40 @@
+"""
+    计数排序
+
+    Author: Wenru
+"""
+
+from typing import List
+import itertools
+
+def counting_sort(a: List[int]):
+    if len(a) <= 1: return
+    
+    # a中有counts[i]个数不大于i
+    counts = [0] * (max(a) + 1)
+    for num in a:
+        counts[num] += 1
+    counts = list(itertools.accumulate(counts))
+
+    # 临时数组，储存排序之后的结果
+    a_sorted = [0] * len(a)
+    for num in reversed(a):
+        index = counts[num] - 1
+        a_sorted[index] = num
+        counts[num] -= 1
+    
+    a = a_sorted
+
+
+if __name__ == "__main__":
+    a1 = [1, 2, 3, 4]
+    counting_sort(a1)
+    print(a1)
+
+    a2 = [1, 1, 1, 1]
+    counting_sort(a2)
+    print(a2)
+
+    a3 = [4, 5, 0, 9, 3, 3, 1, 9, 8, 7]
+    counting_sort(a3)
+    print(a3)
--- a/python/15_bsearch/bsearch.py
+++ b/python/15_bsearch/bsearch.py
@ -0,0 +1,22 @@
+"""
+    Author: Wenru
+"""
+
+from typing import List
+
+def bsearch(nums: List[int], target: int) -> int:
+    """Binary search of a target in a sorted array
+    without duplicates. If such a target does not exist,
+    return -1, othewise, return its index.
+    """
+    low, high = 0, len(nums) - 1
+    while low <= high:
+        mid = low + (high - low) // 2
+        if nums[mid] == target:
+            return mid
+        elif nums[mid] < target:
+            low = mid + 1
+        else:
+            high = mid - 1
+    
+    return -1
--- a/python/16_bsearch/bsearch_variants.py
+++ b/python/16_bsearch/bsearch_variants.py
@ -0,0 +1,77 @@
+"""
+    Author: Wenru
+"""
+
+from typing import List
+
+def bsearch_left(nums: List[int], target: int) -> int:
+    """Binary search of the index of the first element
+    equal to a given target in the ascending sorted array.
+    If not found, return -1.
+    """
+    low, high = 0, len(nums) - 1
+    while low <= high:
+        mid = low + (high - low) // 2
+        if nums[mid] < target:
+            low = mid + 1
+        else:
+            high = mid - 1
+    return low if nums[low] == target else -1
+
+def bsearch_right(nums: List[int], target: int) -> int:
+    """Binary search of the index of the last element
+    equal to a given target in the ascending sorted array.
+    If not found, return -1.
+    """
+    low, high = 0, len(nums) - 1
+    while low <= high:
+        mid = low + (high - low) // 2
+        if nums[mid] <= target:
+            low = mid + 1
+        else:
+            high = mid - 1
+    return high if nums[high] == target else -1
+
+
+def bsearch_left_not_less(nums: List[int], target: int) -> int:
+    """Binary search of the index of the first element
+    not less than a given target in the ascending sorted array.
+    If not found, return -1.
+    """
+    low, high = 0, len(nums) - 1
+    while low <= high:
+        mid = low + (high - low) // 2
+        if nums[mid] < target:
+            low = mid + 1
+        else:
+            high = mid - 1
+    return low if low < len(nums) else -1
+
+def bsearch_right_not_greater(nums: List[int], target: int) -> int:
+    """Binary search of the index of the last element
+    not greater than a given target in the ascending sorted array.
+    If not found, return -1.
+    """
+    low, high = 0, len(nums) - 1
+    while low <= high:
+        mid = low + (high - low) // 2
+        if nums[mid] <= target:
+            low = mid + 1
+        else:
+            high = mid - 1
+    return high if high > 0 else -1
+
+if __name__ == "__main__":
+    import bisect
+
+    a = [0, 1, 1, 2, 3, 4, 5, 6, 6, 7, 8, 8, 10, 10, 10]
+    b = [11, 12, 12, 13, 14, 14, 15, 15]
+    print(bisect.bisect_left(a, 10) == bsearch_left(a, 10))
+    print(bisect.bisect_right(a, 10))
+    print(bisect.bisect_right(a, 6)-1 == bsearch_right(a, 6))
+    print(bisect.bisect_right(b, 14)-1 == bsearch_right(b, 14))
+
+    print(bsearch_left_not_less(a, 11))
+    print(bsearch_right_not_greater(b, 12))
+    print(bsearch_right_not_greater(b, 10))
+    print(bsearch_right_not_greater(b, 17))
--- a/python/array.py
+++ b/python/array.py
@ -0,0 +1,70 @@
+# 1.数组的插入、删除、按照下标随机访问操作；
+# 2.数组中的数据类型是Int
+#
+# Author:Lee
+
+class Array():
+
+    def __init__(self):
+        '''数组类初始化方法.'''
+        self.__data = []  # 数据存储List
+
+    def find(self, index):
+        '''数组的查找方法.
+
+        参数：
+            index:将要查找的数据的下标
+
+        返回：
+            如果查找成功，则返回找到的数据
+            如果查找失败，则返回False
+        '''
+        if index > len(self.__data) or index < 0:
+            return False
+        else:
+            return self.__data[index]
+
+    def delete(self, index):
+        '''数组的删除方法.
+
+        参数：
+            index:将要删除的数据的下标
+
+        返回：
+            如果删除成功，则返回True
+            如果删除失败，则返回False
+        '''
+        if index > len(self.__data) or index < 0:
+            return False
+        else:
+            self.__data.pop(index)
+            return True
+
+    def insert(self, index, value):
+        '''数组插入数据操作.
+
+        参数：
+            index:将要插入的下标
+            value：将要插入的数据
+
+        返回：
+            如果插入成功，则返回True
+            如果插入失败，则返回False
+        '''
+        if index > len(self.__data) or index < 0:
+            return False
+        else:
+            self.__data.insert(index, value)
+            return True
+
+    def insertToTail(self, value):
+        '''直接在数组尾部插入数据.
+
+        参数：
+            value:将要插入的数据
+        '''
+        self.__data.append(value)
+
+    def printAll(self):
+        '''打印当前数组所有数据'''
+        print(self.__data)
--- a/scala/11_sorts/Sorts.scala
+++ b/scala/11_sorts/Sorts.scala
@ -0,0 +1,68 @@
+import scala.util.control.Breaks._
+
+/**
+  * 冒泡排序、插入排序、选择排序
+  *
+  * Author: yangchuz
+  */
+object Sorts {
+  def main(args: Array[String]): Unit ={
+//    println(bubbleSort(Array(0, 6, 2, 3, 8, 5, 6, 7), 8).mkString(", "))
+//    println(insertSort(Array(0, 6, 2, 3, 8, 5, 6, 7), 8).mkString(", "))
+    println(selectionSort(Array(0, 6, 2, 3, 8, 5, 6, 7), 8).mkString(", "))
+  }
+
+  def bubbleSort(arr: Array[Int], n:Int): Array[Int] = {
+    val n = arr.length
+    breakable {
+      for(i <- (n-1) to (1, -1)){
+        var flag = false
+        for(j <- 0 until i){
+          if(arr(j) > arr(j+1)){
+            val tmp = arr(j)
+            arr(j) = arr(j+1)
+            arr(j+1) = tmp
+            flag = true
+          }
+        }
+        if(!flag){
+          break
+        }
+      }
+    }
+    arr
+  }
+
+  def insertSort(arr: Array[Int], n:Int): Array[Int] = {
+    for(i <- 1 until n){
+      val tmp = arr(i)
+      breakable{
+        for(j <- (i-1) to (0, -1)){
+          if(tmp < arr(j)){
+            arr(j+1) = arr(j)
+          }else{
+            arr(j+1) = tmp
+            break
+          }
+        }
+      }
+    }
+    arr
+  }
+
+  def selectionSort(arr: Array[Int], n:Int): Array[Int] = {
+    for(i <- 0 until n){
+      var min = i
+      for(j <- (i + 1) until n){
+        if(arr(j) < arr(min)){
+          min = j
+        }
+      }
+
+      val tmp = arr(i)
+      arr(i) = arr(min)
+      arr(min) = tmp
+    }
+    arr
+  }
+}
--- a/swift/12_sorts/.DS_Store
+++ b/swift/12_sorts/.DS_Store
--- a/swift/12_sorts/QuickSort.swift
+++ b/swift/12_sorts/QuickSort.swift
@ -0,0 +1,36 @@
+//
+//  QuickSort.swift
+//  algo
+//
+//  Created by Wenru Dong on 2018/10/17.
+//  Copyright © 2018年 Wenru Dong. All rights reserved.
+//
+
+import Foundation
+
+public func quickSort<T: RandomAccessCollection & MutableCollection>(_ a: inout T) where T.Element: Comparable {
+    quickSort(&a, from: a.startIndex, to: a.index(before: a.endIndex))
+}
+
+fileprivate func quickSort<T: RandomAccessCollection & MutableCollection>(_ a: inout T, from low: T.Index, to high: T.Index) where T.Element: Comparable {
+    if low >= high { return }
+    
+    let m = partition(&a, from: low, to: high)
+    quickSort(&a, from: low, to: a.index(before: m))
+    quickSort(&a, from: a.index(after: m), to: high)
+}
+
+fileprivate func partition<T: RandomAccessCollection & MutableCollection>(_ a: inout T, from low: T.Index, to high: T.Index) -> T.Index where T.Element: Comparable {
+    let pivot = a[low]
+    var j = low
+    var i = a.index(after: low)
+    while i <= high {
+        if a[i] < pivot {
+            a.formIndex(after: &j)
+            a.swapAt(i, j)
+        }
+        a.formIndex(after: &i)
+    }
+    a.swapAt(low, j)
+    return j
+}
--- a/swift/12_sorts/SortsTests.swift
+++ b/swift/12_sorts/SortsTests.swift
@ -0,0 +1,58 @@
+//
+//  SortsTests.swift
+//  SortsTests
+//
+//  Created by Wenru Dong on 2018/10/14.
+//  Copyright © 2018年 Wenru Dong. All rights reserved.
+//
+
+import XCTest
+
+class SortsTests: XCTestCase {
+    
+    override func setUp() {
+        super.setUp()
+        // Put setup code here. This method is called before the invocation of each test method in the class.
+    }
+    
+    override func tearDown() {
+        // Put teardown code here. This method is called after the invocation of each test method in the class.
+        super.tearDown()
+    }
+    
+    func testMergeSort() {
+        var a1 = [1, 1, 1, 1]
+        mergeSort(&a1)
+        XCTAssertEqual(a1, [1, 1, 1, 1])
+        
+        var a2 = [4, 3, 2, 1]
+        mergeSort(&a2)
+        XCTAssertEqual(a2, [1, 2, 3, 4])
+        
+        var a3 = [3, 6, 9, 7, 8, -1, 9, 3, -2, 0]
+        mergeSort(&a3)
+        XCTAssertEqual(a3, [-2, -1, 0, 3, 3, 6, 7, 8, 9, 9])
+    }
+    
+    func testQuickSort() {
+        var a1 = [1, 1, 1, 1]
+        quickSort(&a1)
+        XCTAssertEqual(a1, [1, 1, 1, 1])
+        
+        var a2 = [4, 3, 2, 1]
+        quickSort(&a2)
+        XCTAssertEqual(a2, [1, 2, 3, 4])
+        
+        var a3 = [3, 6, 9, 7, 8, -1, 9, 3, -2, 0]
+        quickSort(&a3)
+        XCTAssertEqual(a3, [-2, -1, 0, 3, 3, 6, 7, 8, 9, 9])
+    }
+    
+    func testPerformanceExample() {
+        // This is an example of a performance test case.
+        self.measure {
+            // Put the code you want to measure the time of here.
+        }
+    }
+    
+}
--- a/swift/12_sorts/mergeSort.swift
+++ b/swift/12_sorts/mergeSort.swift
@ -0,0 +1,52 @@
+//
+//  sorts.swift
+//  algo
+//
+//  Created by Wenru Dong on 2018/10/14.
+//  Copyright © 2018年 Wenru Dong. All rights reserved.
+//
+
+import Foundation
+
+public func mergeSort<T>(_ a: inout T) where T: RandomAccessCollection, T: MutableCollection, T.Element: Comparable {
+    mergeSort(&a, from: a.startIndex, to: a.index(before: a.endIndex))
+}
+
+fileprivate func mergeSort<T>(_ a: inout T, from low: T.Index, to high: T.Index) where T: RandomAccessCollection, T: MutableCollection, T.Element: Comparable {
+    if low >= high { return }
+    let dist = a.distance(from: low, to: high)
+    let mid = a.index(low, offsetBy: dist/2)
+    mergeSort(&a, from: low, to: mid)
+    mergeSort(&a, from: a.index(mid, offsetBy: 1), to: high)
+    merge(&a, from: low, through: mid, to: high)
+}
+
+fileprivate func merge<T>(_ a: inout T, from low: T.Index, through mid: T.Index, to high: T.Index) where T: RandomAccessCollection, T: MutableCollection, T.Element: Comparable {
+    var i = low
+    var j = a.index(mid, offsetBy: 1)
+    var tmp = Array<T.Element>()
+    tmp.reserveCapacity(a.distance(from: low, to: high) + 1)
+    while i <= mid && j <= high {
+        if a[i] <= a[j] {
+            tmp.append(a[i])
+            a.formIndex(after: &i)
+        } else {
+            tmp.append(a[j])
+            a.formIndex(after: &j)
+        }
+    }
+    
+    var start = i
+    var end = mid
+    if j <= high {
+        start = j
+        end = high
+    }
+    tmp.append(contentsOf: a[start...end])
+    
+    var current = low
+    for element in tmp {
+        a[current] = element
+        a.formIndex(after: &current)
+    }
+}
--- a/swift/14_sorts/CountingSort.swift
+++ b/swift/14_sorts/CountingSort.swift
@ -0,0 +1,33 @@
+//
+//  CountingSort.swift
+//  algo
+//
+//  Created by Wenru Dong on 2018/10/18.
+//  Copyright © 2018年 Wenru Dong. All rights reserved.
+//
+
+import Foundation
+
+// 假设数组中储存的都是非负整数
+public func countingSort(_ a: inout [Int]) {
+    if a.count <= 1 { return }
+    
+    var counts = Array(repeating: 0, count: a.max()! + 1)
+    for num in a {
+        counts[num] += 1
+    }
+    for i in 1..<counts.count {
+        counts[i] = counts[i-1] + counts[i]
+    }
+    
+    var aSorted = Array(repeating: 0, count: a.count)
+    for num in a.reversed() {
+        let index = counts[num] - 1
+        aSorted[index] = num
+        counts[num] -= 1
+    }
+    
+    for (i, num) in aSorted.enumerated() {
+        a[i] = num
+    }
+}