Merge pull request #176 from RichardWeiYang/master

BST and Heap

c-cpp/24_binarysearchtree/bst.c

@@ -0,0 +1,197 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+#include <time.h>
+
+enum child_dir {
+	left_child,
+	right_child,
+	root,
+};
+
+struct node {
+	unsigned long data; 
+	struct node *left;
+	struct node *right;
+};
+
+struct root {
+	struct node *r;
+};
+
+void dump(struct node *node, int level, enum child_dir dir)
+{
+	if (!node)
+		return;
+
+	dump(node->right, level + 1, right_child);
+
+	if (dir == left_child)
+		printf("%*s\n", level*3, "|");
+
+	printf("%*s - %05lu\n", level*3, " ", node->data);
+
+	if (dir == right_child)
+		printf("%*s\n", level*3, "|");
+
+	dump(node->left, level + 1, left_child);
+}
+
+struct node* find(struct root *root, unsigned long data)
+{
+	struct node* n = root->r;
+
+	while (n) {
+		if (n->data == data)
+			return n;
+		if (data < n->data)
+			n = n->left;
+		else
+			n = n->right;
+	}
+
+	return NULL;
+}
+
+struct node* new_node(unsigned long data)
+{
+	struct node *n;
+
+	n = malloc(sizeof(struct node));
+
+	n->data = data;
+	n->left = n->right = NULL;
+	return n;
+}
+
+void insert(struct root *root, struct node *new)
+{
+	struct node *parent;
+
+	if (!root->r) {
+		root->r = new;
+		return;
+	}
+
+	parent = root->r;
+
+	while (true) {
+		/* Don't support duplicate data */
+		if (new->data == parent->data)
+			break;
+
+		if (new->data < parent->data) {
+			if (!parent->left) {
+				parent->left = new;
+				break;
+			}
+			parent = parent->left;
+		} else {
+			if (!parent->right) {
+				parent->right = new;
+				break;
+			}
+			parent = parent->right;
+		}
+	}
+}
+
+struct node* delete(struct root *root, unsigned long data)
+{
+	struct node *n = root->r, **p = &root->r;
+	struct node *child;
+
+	while (n && n->data != data) {
+		if (data < n->data) {
+			p = &n->left;
+			n = n->left;
+		} else {
+			p = &n->right;
+			n = n->right;
+		}
+	}
+
+	if (!n)
+		return NULL;
+	
+	if (n->left && n->right) {
+		struct node *rn = n->right, **rp = &n->right;
+
+		while (rn->left) {
+			rp = &rn->left;
+			rn = rn->left;
+		}
+
+		n->data = rn->data;
+		n = rn;
+		p = rp;
+	}
+
+	child = n->left ? n->left : n->right;
+	*p = child;
+
+	return NULL;
+}
+
+void insert_test()
+{
+	struct root tree;
+	struct node* n;
+
+	tree.r = NULL;
+
+	insert(&tree, new_node(9));
+
+	insert(&tree, new_node(5));
+	insert(&tree, new_node(2));
+	insert(&tree, new_node(8));
+
+	insert(&tree, new_node(18));
+	insert(&tree, new_node(13));
+	insert(&tree, new_node(21));
+	insert(&tree, new_node(20));
+
+	dump(tree.r, 0, root);
+
+	n = find(&tree, 18);
+	if (n && n->data == 18)
+		printf("Get 18\n");
+
+}
+
+void delete_test()
+{
+	struct root tree;
+	struct node* n;
+
+	tree.r = NULL;
+
+	insert(&tree, new_node(9));
+
+	insert(&tree, new_node(5));
+	insert(&tree, new_node(2));
+	insert(&tree, new_node(8));
+
+	insert(&tree, new_node(18));
+	insert(&tree, new_node(13));
+	insert(&tree, new_node(21));
+	insert(&tree, new_node(20));
+
+	dump(tree.r, 0, root);
+
+	delete(&tree, 20);
+	printf("Delete 20\n");
+	dump(tree.r, 0, root);
+
+	delete(&tree, 9);
+	printf("Delete 9\n");
+	dump(tree.r, 0, root);
+}
+
+int main()
+{
+	//insert_test();
+	delete_test();
+	return 0;
+}

c-cpp/28_heap/heap.c

@@ -0,0 +1,160 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+#include <time.h>
+
+/* Implement heap */
+
+#define MAX_HEAP_SIZE (1 << 8)
+
+struct element {
+	int data;
+};
+
+struct heap {
+	union {
+		unsigned long elements;
+		struct element *elem[MAX_HEAP_SIZE];
+	};
+};
+
+void init_heap(struct heap *heap)
+{
+	int i;
+
+	for(i = 0; i < MAX_HEAP_SIZE; i++) {
+		heap->elem[i] = NULL;
+	}
+}
+
+void dump_heap(struct heap *heap, int index)
+{
+	struct element *elem;
+	int level;
+
+	if (index > heap->elements)
+		return;
+
+	elem = heap->elem[index];
+	level = fls(index);
+
+	dump_heap(heap, index * 2 + 1);
+
+	if (!(index % 2) && index != 1)
+		printf("%*s\n", level*3, "|");
+
+	printf("%*s - %05d\n", level*3, " ", elem->data);
+
+	if (index % 2 && index != 1)
+		printf("%*s\n", level*3, "|");
+
+	dump_heap(heap, index * 2);
+}
+
+void dump(struct heap *heap, int elements)
+{
+	int i;
+
+	for (i = 1; i <= elements; i++)
+		printf("[%02d]: %4d\n", i, heap->elem[i]->data);
+
+}
+
+struct element* create_element(int data)
+{
+	struct element *elem;
+
+	elem = malloc(sizeof(struct element));
+
+	if (elem)
+		elem->data = data;
+
+	return elem;
+}
+
+void fake_a_heap(struct heap *heap)
+{
+	/* data is in ordered */
+	int i, data[10] = {7, 4, 9, 2, 6, 8, 10, 1, 3, 5};
+
+	init_heap(heap);
+
+	/* root start at 1 */
+	for (i = 0; i < 10; i++)
+		heap->elem[i+1] = create_element(data[i]);
+
+	heap->elements = 10;
+}
+
+void swap(struct heap *heap, int i, int j)
+{
+	struct element *tmp;
+
+	tmp = heap->elem[j];
+	heap->elem[j] = heap->elem[i];
+	heap->elem[i] = tmp;
+}
+
+void heapify(struct heap *heap, int parent)
+{
+	struct element **elem = heap->elem;
+	int elements = heap->elements;
+	int left, right, max;
+
+	while (true) {
+		left = parent * 2;
+		right = left + 1;
+		
+		max = parent;
+		if (left <= elements && elem[max]->data < elem[left]->data)
+			max = left;
+		if (right <= elements && elem[max]->data < elem[right]->data)
+			max = right;
+
+		if (max == parent)
+			break;
+
+		swap(heap, max, parent);
+		parent = max;
+	}
+}
+
+void build_heap(struct heap *heap)
+{
+	int i;
+
+	for (i = heap->elements / 2; i >= 1; i--)
+		heapify(heap, i);
+}
+
+int heap_sort(struct heap *heap)
+{
+	int elements = heap->elements;
+
+	while (heap->elements) {
+		swap(heap, 1, heap->elements);
+		heap->elements--;
+		heapify(heap, 1);
+	}
+	
+	return elements;
+}
+
+int main()
+{
+	struct heap heap;
+	int elements;
+
+	fake_a_heap(&heap);
+	dump_heap(&heap, 1);
+
+	printf("After Heapify:\n");
+	build_heap(&heap);
+	dump_heap(&heap, 1);
+
+	printf("After Heap sort:\n");
+	elements = heap_sort(&heap);
+	dump(&heap, elements);
+	return 0;
+}