我过关！

代码：

#include <iostream>
using namespace std;

string itos(int input){
    if(input<10) {
        string s="x";
        s[0]='0'+input;
        return s;
    }
    string s = itos(input/10) + itos(input%10);
    return s;
}

string once(string input){
    int in1 = 0,in2;
    string ans = "";
    char ch3;
    while (in1<input.size()){
        in2=0;
        ch3=input[in1];
        while(input[in1]==ch3){
            in1++;
            in2++;
        }
        ans += itos(in2)+ch3;
    }
    return ans;
}

int main(){
    string s;
    int n;
    cin>>s>>n;
    for(int i = 0; i<n; i++){
        s = once(s);
    }
    cout<<s;
    return 0;
}