The correct, optimal and working solution for programming question sherlock-and-divisors on hackerrank

/* * Author: Arpit Bhayani * https://arpitbhayani.me */ #include <cmath> #include <cstdio> #include <cstdlib> #include <climits> #include <deque> #include <iostream> #include <list> #include <limits> #include <map> #include <queue> #include <set> #include <stack> #include <vector> #define ll long long #define MIN(a, b) a < b ? a : b #define MAX(a, b) a > b ? a : b using namespace std; int readline(char *str) { int i = 0; char ch; while((ch = getchar()) != '\n') { str[i++] = ch; } str[i] = '\0'; return i; } int main(int argc, char *argv[]) { int t; scanf("%d", &t); while(t--) { ll int n, m, count = 0; cin >> n; m = (ll int) sqrt(n); for(int i = 1; i <= m; i++) { ll int f1 = i, f2 = n/i; if(n % f1 == 0) { if(f1 % 2 == 0) { count++; } if(f2 % 2 == 0) { count++; } if(f1 % 2 == 0 && f1 == f2) { count--; } } } cout << count << endl; } return 0; }