题解

#include<bits/stdc++.h>
using namespace std;
int main()
{
    string s;
    int n;
    cin >> s >> n;
    while (n--)
    {
        string t;
        for (int i = 0; i < s.size();)
        {
            int j = i;
            while (j < s.size() && s[j] == s[i]) j++;
            int cnt = j - i;
            t += (to_string(cnt) + s[i]);
            i = j;
        }
        s = t;
    }
    cout << s <<endl;
}