Compile-Time Timer Reload

#include <iostream>
using namespace std;

// Define constexpr computeReload here
constexpr int computeReload(int clockHz, int intervalMs){
    return (clockHz * intervalMs + 500) / 1000;
}

#define TIMERCLKHZ 1000000

// Define constexpr RELOAD_TABLE here

constexpr int RELOAD_TABLE[3] = {computeReload(TIMERCLKHZ, 1), computeReload(TIMERCLKHZ, 10), computeReload(TIMERCLKHZ, 100)};

int main() {
    int idx;
    cin >> idx;

    cout << RELOAD_TABLE[idx];

    return 0;
}

Solving Approach