二叉树层次遍历

#include <iostream>
#include <stdio.h>
#include <stdlib.h>
#define maxsize 10
using namespace std;
typedef struct BTNode{
  char  data;
  struct BTNode *lchild;
  struct BTNode *rchild;
}BTNode;
void create(BTNode *&p)  //先序遍历创建二叉树
{
    char k;
    scanf("%c",&k);
    if(k=='#') p=NULL;
    else
    {
        p=(BTNode *)malloc(sizeof(BTNode));
        p->data=k;
        create(p->lchild);
        create(p->rchild);
    }
}

void level(BTNode *p)
{
    BTNode *q;
    BTNode *queue[maxsize];
    int front=0,rear=0;
    if(p==NULL) return;
    else
    {
        rear=(rear+1)%maxsize;
        queue[rear]=p;
        while(front!=rear)
        {
            front=(front+1)%maxsize;
            q=queue[front];
            printf("%c ",q->data);
            if(q->lchild!=NULL) {rear=(rear+1)%maxsize;queue[rear]=q->lchild;}
            if(q->rchild!=NULL) {rear=(rear+1)%maxsize;queue[rear]=q->rchild;}
        }
    }
}
int main()
{
    BTNode *T;
    create(T);
    level(T);
    return 0;
}