二叉树链式存储的实现

//filename:bitree.h

#include <stdio.h>
#include <stdlib.h>
#include <malloc.h>

#define OK 1
#define ERROR 0
#define TRUE 1
#define FALSE 0

#define NIL '#'	//定义'#'为空节点

typedef struct queue_node qnode;
typedef struct bitree_node bitree;

struct bitree_node
{
char elem;
bitree *lchild;
bitree *rchild;
};

/*队列节点*/
struct queue_node
{
bitree *btn;
qnode *next;
};

typedef struct link_queue
{
qnode *head;
qnode *tail;
}queue;

/*****队列的基本操作******/
int init_link_queue(queue *Q);
int is_queue_empty(queue Q);
int enqueue(queue *Q, bitree *btn);
int dequeue(queue *Q, char *elem);

/*****二叉树的操作*****/
bitree *create_bitree();
int is_bitree_empty(bitree *btn);
int get_bitree_depth(bitree *btn);
bitree *get_parent(bitree *btn, char elem);
int preorder_traverse(bitree *btn, int (*visit)(char));
int inorder_traverse(bitree *btn, int (*visit)(char));
int postorder_traverse(bitree *btn, int (*visit)(char));
int levelorder_traverse(bitree *btn, int (*visit)(char));
int destory_bitree(bitree *btn);
int print_elem(char elem);

//filename:queue.c#include "bitree.h"/*功能：链队列初始化*/int init_link_queue(queue *Q){qnode *tmp_node = (qnode *)malloc(sizeof(qnode));if(!tmp_node){return ERROR;}tmp_node->btn = NULL;tmp_node->next = NULL;Q->head = tmp_node;Q->tail = tmp_node;return OK;}/*功能：队列是否为空返回：1 空；0 非空*/int is_queue_empty(queue Q){return ((Q.head == Q.tail) ? TRUE : FALSE);}/*功能：元素num入队*/int enqueue(queue *Q, bitree *btn){qnode *tmp_node = (qnode *)malloc(sizeof(qnode));if(!tmp_node){return ERROR;}tmp_node->next = NULL;tmp_node->btn = btn;Q->tail->next = tmp_node;Q->tail = tmp_node;return OK;}/*功能：出队，队头元素存入num参数：	Q	队列；btn_addr 存放出队节点内的bitree *地址*/int dequeue(queue *Q, int *btn_addr){qnode *tmp_node = NULL;if(is_queue_empty(*Q)){return ERROR;}tmp_node = Q->head->next;Q->head->next = tmp_node->next;*btn_addr = tmp_node->btn;if(Q->head->next == NULL){Q->tail = Q->head;}free(tmp_node);return OK;}

//filename:bitree.c#include "bitree.h"/*功能：先序创建二叉树返回：创建的节点地址*/bitree *create_bitree(){char elem;bitree *btn = NULL;fflush(stdin);	//清空输入缓冲流scanf("%c", &elem);if(elem == NIL){return btn;}else{btn = (bitree *)malloc(sizeof(bitree));btn->elem = elem;btn->lchild = create_bitree();btn->rchild = create_bitree();return btn;}}/*功能：判断该二叉树是否为空返回：1 空； 0 非空*/int is_bitree_empty(bitree *btn){if(!btn){return TRUE;}else{return FALSE;}}/*功能：求二叉树的深度*/int get_bitree_depth(bitree *btn){int i = 0;	//记录左子树深度int j = 0;	//记录右子树深度if(!btn){return 0;}if(btn->lchild){i = get_bitree_depth(btn->lchild);}else{i = 0;}if(btn->rchild){j = get_bitree_depth(btn->rchild);}else{j = 0;}return (i > j) ? (i + 1) : (j + 1);}/*功能：获取元素elem节点的父结点返回：如果elem为根，返回NULL；*/bitree *get_parent(bitree *btn, char elem){int btn_addr = 0;bitree *father_node = NULL;queue Q;if(!btn)		//树为空{return NULL;}init_link_queue(&Q);	//初始化队列enqueue(&Q, btn);while(!is_queue_empty(Q))	//队列不为空{dequeue(&Q, &btn_addr);father_node = btn_addr;if((father_node->lchild && father_node->lchild->elem == elem) ||(father_node->rchild && father_node->rchild->elem == elem)){return father_node;}else{if(father_node->lchild){enqueue(&Q, father_node->lchild);}if(father_node->rchild){enqueue(&Q, father_node->rchild);}}}return NULL;}/*功能：先序遍历二叉树*/int preorder_traverse(bitree *btn, int (*visit)(char)){if(!btn){return OK;}visit(btn->elem);preorder_traverse(btn->lchild, visit);preorder_traverse(btn->rchild, visit);return OK;}/*功能：中序遍历二叉树*/int inorder_traverse(bitree *btn, int (*visit)(char)){if(!btn){return OK;}inorder_traverse(btn->lchild, visit);visit(btn->elem);inorder_traverse(btn->rchild, visit);return OK;}/*功能：后序遍历二叉树*/int postorder_traverse(bitree *btn, int (*visit)(char)){if(!btn){return OK;}postorder_traverse(btn->lchild, visit);postorder_traverse(btn->rchild, visit);visit(btn->elem);return OK;}/*功能：按层序遍历二叉树，借助队列*/int levelorder_traverse(bitree *btn, int (*visit)(char)){int btn_addr = 0;		//记录出队的队列节点的(bitree *)的地址bitree *bitree_node = NULL;queue Q;if(!btn)		//树为空{return NULL;}init_link_queue(&Q);	//初始化队列enqueue(&Q, btn);while(!is_queue_empty(Q))	//队列不为空{dequeue(&Q, &btn_addr);bitree_node = btn_addr;visit(bitree_node->elem);if(bitree_node->lchild){enqueue(&Q, bitree_node->lchild);}if(bitree_node->rchild){enqueue(&Q, bitree_node->rchild);}}return NULL;}/*功能：	销毁二叉树*/int destory_bitree(bitree *btn){if(btn){if(btn->lchild){destory_bitree(btn->lchild);}if(btn->rchild){destory_bitree(btn->rchild);}free(btn);btn = NULL;}return OK;}/*功能：打印传入的参数值*/int print_elem(char elem){printf("%c ", elem);return OK;}

//filename:test_bitree.c#include "bitree.h"/*测试数据：	先序创建树：abd###c##;先序遍历：	abdc中序遍历：	dbac后序遍历：	dbca*/int main(int argc, char *argv[]){bitree *tmpnode = NULL;bitree *bitree = NULL;bitree = create_bitree();preorder_traverse(bitree, print_elem);printf("\n");inorder_traverse(bitree, print_elem);printf("\n");postorder_traverse(bitree, print_elem);printf("\n");levelorder_traverse(bitree, print_elem);printf("\n");printf("the depth of the bitree is %d.\n", get_bitree_depth(bitree));tmpnode = get_parent(bitree, 'd');printf("the 'd' father node is:%c\n", tmpnode->elem);destory_bitree(bitree);system("pause");return 0;}