Problem: 367. 有效的完全平方数

思路

和704二分查找非常的一样

Code

class Solution(object):
    def isPerfectSquare(self, num):
        """
        :type num: int
        :rtype: bool
        """
        l = 0
        r = num
        while(l <= r):
            mid = (l + r) // 2
            if mid * mid < num:
                l = mid + 1
            elif mid * mid > num:
                r = mid - 1
            else:
                return True
        return False