367. Valid Perfect Square

Given a positive integer num, write a function which returns True if num is a perfect square else False.

Follow up: Do not use any built-in library function such as sqrt.

Example 1: Input: num = 16 Output: true Example 2:

Input: num = 14 Output: false

Constraints:

• 1 <= num <= 2^31 - 1

Solution:

/**
 * @param {number} num
 * @return {boolean}
 */
var isPerfectSquare = function(num) {
  var n = num ** 0.5;
  if(n % 1 > 0) return false;
  return true;
};