HIIT remains

input/code.cpp: In function 'int main()':
input/code.cpp:21:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   21 |         for (int i = 0; i < s.size(); i++)
      |                         ~~^~~~~~~~~~

// Online C++ compiler to run C++ program online
#include <iostream>
#include <iomanip>
#include <vector>
#include <cmath>
using namespace std;
int main() {
    int n;
    cin >> n;
    
    string s;
    
    for (int test = 0; test < n; test++)
    {
        cin >> s;
        long long h = 0;
        long long hi = 0;
        long long hii = 0;
        long long hiit = 0;
        
        for (int i = 0; i < s.size(); i++)
        {
            if (s[i] == 'H')
                h++;
            if (s[i] == 'I')
            {
                hii += hi;
                hi += h;
            }
            if (s[i] == 'T')
                hiit += hii;
        }
        
        cout << hiit << endl;
    }

    return 0;
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED