function isPerfectSquare(num){
 let l=1,r=num;
 while(l<=r){
  const m=l+Math.floor((r-l)/2);
  const sq=m*m;
  if(sq===num) return true;
  if(sq<num) l=m+1; else r=m-1;
 }
 return false;
}
console.log(isPerfectSquare(16));

function isPerfectSquare(num:number):boolean{
 let l=1,r=num;
 while(l<=r){
  const m=l+Math.floor((r-l)/2);
  const sq=m*m;
  if(sq===num) return true;
  if(sq<num) l=m+1; else r=m-1;
 }
 return false;
}
console.log(isPerfectSquare(16));

package main

import "fmt"

func isPerfectSquare(num int) bool {
	l, r := 1, num
	for l <= r {
		m := l + (r-l)/2
		sq := m * m
		if sq == num {
			return true
		}
		if sq < num {
			l = m + 1
		} else {
			r = m - 1
		}
	}
	return false
}

func main() {
	fmt.Println(isPerfectSquare(16))
}

fn is_perfect_square(num: i64) -> bool {
	let (mut l, mut r) = (1i64, num);
	while l <= r {
		let m = l + (r - l) / 2;
		let sq = m * m;
		if sq == num { return true; }
		if sq < num { l = m + 1; } else { r = m - 1; }
	}
	false
}
fn main() {}