HIIT Generation

#include <iostream>
#include <stdio.h>

using namespace std;

char x[1000000];
int n;

void r(char a, int y) {
    if (y == n) {
        putchar_unlocked(a);
        return;
    }
    if (x[y] == a) {
        r('H', y+1);
        r('I', y+1);
        r('I', y+1);
        r('T', y+1);
    } else {
        r(a, y+1);
    }
}

int main() {
    cin >> n;
    for (int i = 0; i < n; i++) {
        cin >> x[i];
    }
    
    r('H', 0);
    r('I', 0);
    r('I', 0);
    r('T', 0);
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: TIME LIMIT EXCEEDED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED