The correct, optimal and working solution for programming question sherlock-and-squares 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 a, b; cin >> a >> b; int x = ceil(sqrt(a)); int y = floor(sqrt(b)); cout << (y - x) + 1 << endl; } return 0; }