B. The String Has a Target.cpp

#ifdef DEBUG
#include "debug.h"
#endif // DEBUG
#ifndef DEBUG
template <typename T>
void debug(T &x){}
#endif // DEBUG

#include <bits/stdc++.h>

using namespace std;

int main(){
    cin.tie(nullptr), ios::sync_with_stdio(false);
    int t;
    cin >> t;
    while(t--){
        int n;
        string s;
        cin >> n >> s;
        char minc = 'z';
        int minp;

        for(int i = 0; i < n; i++){
            if(s[i] <= minc){
                minc = s[i];
                minp = i;
            }
        }

        char tmp = s[minp];
        s.erase(s.begin() + minp);
        cout << tmp << s << "\n";
    }
}