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 constexpr RELOAD_TABLE here
constexpr int RELOAD_TABLE[3] = {computeReload(1'000'000,1),computeReload(1'000'000,10),computeReload(1'000'000,100)};
int main() {
    int idx;
    cin >> idx;

    // Print RELOAD_TABLE[idx]
    cout << RELOAD_TABLE[idx];
    return 0;
}

Solving Approach