文件解压 //problem/2928 or /contest/1709/problem/3

字符串套 递归

#include<bits/stdc++.h>
using namespace std;
char s[1005];
int n,i;
string work(){
    string p; int t = 0;
    while(++i <= n){
        if(s[i] >= '0' && s[i] <= '9'){
            t = s[i] - '0';
        }
        else if(s[i] == '('){
            string pp = work();
            while(t--) p += pp;
            t = 0;
        }
        else if(s[i] == ')') return p;
        else p += s[i];        
    }
    return p;
}
int main(){
    cin>>s+1; n = strlen(s+1);
    cout<<work();
    return 0;
}

zgy:

 rty