求一个二叉树的M层的第K个节点的值

/*
 * Copyright (c) 2010-~ zhouyongfei
 *
 * The source code is released for free distribution under the terms of the GNU General Public License
 *
 *
 * Author: alen Chou<[email protected]>
 * Created Time: 2010年05月31日 星期一 18时37分59秒
 * File Name: test.c
 * Description: 这个程序用于遍历二叉树M层第K个元素的值

 × 示例：输入124..56..7..3..

 × 输出：result is 7
 *
 */

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


typedef struct Node{
    char data;
    struct Node * Lchild;
    struct Node * Rchild;
    int level;
}BiTNode,*BiTree;//二叉树节点，二叉链表


typedef struct QueueNode{
    BiTree data;
    struct QueueNode *next;
}LinkQueueNode;//队列中的每个节点


typedef struct
{
    LinkQueueNode *front;
    LinkQueueNode *rear;
}LinkQueue;//队列


/*
 * 队列的初始化
 *
 * */
void InitQueue(LinkQueue *Q)
{
    Q->front = (LinkQueueNode *)malloc(sizeof(LinkQueueNode));
    if(Q->front != NULL){
        Q->rear = Q->front;
        Q->front->next = NULL;
    }else printf("分配空间失败!\n");
}
/*
 * 入队
 *
 * */
void EnterQueue(LinkQueue *Q,BiTree x)
{
    LinkQueueNode *NewNode;
    NewNode = (LinkQueueNode *)malloc(sizeof(LinkQueueNode));
    if(NewNode != NULL){
        NewNode->data = x;
        NewNode->next = NULL;
        Q->rear->next = NewNode;
        Q->rear = NewNode;
    }
}

/*
 *    队列判空
 *
 * */
int QueueIsEmpty(LinkQueue *Q)
{
    if(Q->front == Q->rear)
        return 1;
    else return 0;
}

/*
 * 出队
 *
 * */
void DeleteQueue(LinkQueue *Q,BiTree *x)
{
    LinkQueueNode *p;
    if(Q->front == Q->rear)
        return ;
    p = Q->front->next;
    Q->front->next = p->next;
    if(Q->rear == p)
        Q->rear = Q->front;
    *x = p->data;
    free(p);
}


/*
 * 利用扩展先序遍历序列
 * 创建二叉链表
 */
void CreateBiTree(BiTree *bt)
{
    char ch;
    ch = getchar();
    if(ch == '.') *bt = NULL;
    else
    {
        *bt = (BiTree)malloc (sizeof(BiTNode));
        (*bt)->data = ch;
        (*bt)->level = 0;
        CreateBiTree(&((*bt)->Lchild));
        CreateBiTree(&((*bt)->Rchild));
    }
}

/*
 *    层序遍历
 *     对给定的二叉树进行层序遍历
 *
 * */
char LayerOrder(BiTree root,int m,int k)
{    
    char result[20];
    int i = 0;
    BiTree *x;
    //这里要记得申请空间

    x = (BiTree *)malloc(sizeof(BiTree));
    if(x == NULL){
        printf("内存分配失败!\n");
    }
    LinkQueue *Q;
    Q = (LinkQueue *)malloc(sizeof(LinkQueue));
    InitQueue(Q);
    EnterQueue(Q,root);
    while(!QueueIsEmpty(Q)){
        DeleteQueue(Q,x);
        if((*x)->Lchild) (*x)->Lchild->level = (*x)->level + 1;
        if((*x)->Rchild) (*x)->Rchild->level = (*x)->level + 1;
        if((*x)->level == m){
            result[i] = (*x)->data;
            i++;
        }
        if((*x)->Lchild)EnterQueue(Q,(*x)->Lchild);
        if((*x)->Rchild)EnterQueue(Q,(*x)->Rchild);
    }
    return result[k];
}

int main(int argc , char **argv)
{
    BiTree root;
    CreateBiTree(&root);
    printf("层序遍历:\n");
    char result=LayerOrder(root,3,1);
    printf("result is %c",result);
    printf("\n");
}