递归调用求后序

#include<bits/stdc++.h>
using namespace std;
string zhong,qian;
void hou(int l,int r){
    if(l>r){
        return;
    }
    if(l==r){
        cout<<zhong[l];
    }
    char head=qian[l];
    for(int i=l;i<=r;i++){
        if(head==zhong[i]){
            hou(l,i-1);
            hou(i+1,r);
            cout<<head;
            return;
        }
    }
}
int main(){
    cin>>zhong>>qian;
    hou(1,zhong.size());
    return 0;
}