有效的完全平方数-二分查找367-python

class Solution:
    def isPerfectSquare(self, num: int) -> bool:
        left, right = 0, num

        while left <= right:
            mid = int(left + (right - left)/2)

            if mid**2 == num:
                return True
            elif mid**2 > num:
                right = mid - 1
            elif mid**2 < num:
                left = mid + 1
        
        return False