367_Valid_Perfect_Square.js

const isPerfectSquare = (num) => {
  let left = 1;
  let right = num;

  while (left <= right) {
    let mid = Math.floor((left + right) / 2);

    if (mid * mid < num) {
      left = mid + 1;
    } else if (mid * mid > num) {
      right = mid - 1;
    } else {
      return true;
    }
  }

  return false;
};