ACM题目————已知前序和中序求后序

#include <iostream>
#include <cstring>
#include <cstdio>

using namespace std;
char qianxu[30],  zhongxu[30];

void Print_(char* qian, char* zhong, int len){
    char ch = *qian;//根节点
    if( len == 0 ) return ;
    int i=0;
    for(; i<len; i++ ){
        if( zhong[i] == *qian )
            break ;
    } 
    Print_(qian+1, zhong, i);//左子树
    Print_(qian+i+1, zhong+i+1, len-(i+1) ) ;//右子树 
    printf("%c",ch);
}

int main(){
    while(~scanf("%s%s",qianxu,zhongxu) ){
        Print_(qianxu, zhongxu, strlen(qianxu));
        printf("\n");
    }
    return 0;
}