Valid Perfect Square

Problem Statement

Given a positive integer num, return true if num is a perfect square or false otherwise.

A perfect square is an integer that is the square of an integer. In other words, it is the product of some integer with itself.

You must not use any built-in library function, such as sqrt.

Leetcode Link

Example 1:

Input: num = 16
Output: true

Explanation: We return true because 4 * 4 = 16 and 4 is an integer.

Example 2:

Input: num = 14
Output: false

Explanation: We return false because 3.742 * 3.742 = 14 and 3.742 is not an integer.

Constraints:

• 1 <= num <= 2³¹ -1

Code

Python

class Solution5:
    def isPerfectSquare(self, num: int) -> bool:
        if num==1:
            return True
        for i in range(2,num//2+1):
            if num/i < i:
                break
            if num/i == i:
                return True
        return False