树的深度、顺序输出树

#include <stdio.h>
#include <stdlib.h>
#include <queue>
using namespace std;
typedef struct BiTNode{
    int value;
    struct BiTNode *lchild;
    struct BiTNode *rchild;
}BiTNode,*BiTree;
BiTree rebuild(int perorder[],int perstart,int perend,int inorder[],int instart,int inend){//后序与中序构建一棵树(顺序可变，只需做少许改动)
    if(perend-perstart!=inend-instart){
        return NULL;
    }
    if(perstart>perend){
        return NULL;
    }
    BiTree tree=(BiTree)malloc(sizeof(BiTNode));
    tree->value=perorder[perend];
    tree->lchild=NULL;
    tree->rchild=NULL;
    if(perstart==perend){
        return tree;
    }
    int index,length;
    for(index=instart;index<=inend;index++){
        if(perorder[perend]==inorder[index])
        break;
    }
    if(index>inend){
        return NULL;
    }
    if(index>instart){
        length=index-instart;
        tree->lchild=rebuild(perorder,perstart,perstart+length-1,inorder,instart,instart+length-1);
    }
    if(index<inend){
        length=inend-index;
        tree->rchild=rebuild(perorder,perend-length,perend-1,inorder,inend-length+1,inend);
    }
    return tree;
}
int dtree(BiTree t){//求树的深度
    int deep=0;
    if(t){
        int ldeep=dtree(t->lchild);
        int rdeep=dtree(t->rchild);
        deep=ldeep>=rdeep?ldeep+1:rdeep+1;
    }
    return deep;
}
void bfs(BiTree t){//广度优先顺序输出二叉树
    if(t==NULL){
        return;
    }
    queue<BiTree >q;
    q.push(t);
    while(!q.empty()){
        BiTree s=q.front();
        q.pop();
        printf("%d ",s->value);
        if(s->lchild!=NULL){
            q.push(s->lchild);  
        }
        if(s->rchild!=NULL){
            q.push(s->rchild);
        }
    }
}
int main(){
    int n;
    int perorder[31],inorder[31];
    scanf("%d",&n);
    getchar();
    for(int i=0;i<n;i++){
        scanf("%d",&perorder[i]);
    }
    for(int i=0;i<n;i++){
        scanf("%d",&inorder[i]);
    }
    BiTree tree=rebuild(perorder,0,n-1,inorder,0,n-1);
    bfs(tree);
    return 0;
}