[LeetCode] Valid Perfect Square
Given a positive integer num, write a function which returns True if num is a perfect square else False.
Note: Do not use any built-in library function such as sqrt
.
Example 1:
Input: 16 Returns: True
Example 2:
Input: 14 Returns: False
Credits:
Special thanks to @elmirap for adding this problem and creating all test cases.
不使用sqrt判断一个数是否是完全平方数,
class Solution { public: bool isPerfectSquare(int num) { for (int i = 1; i <= num / i; i++) if (i * i == num) return true; return false; } }; // 0ms