Valid Perfect Square
Desicription
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:
代码语言:javascript复制Input: 16
Output: true
Example 2:
代码语言:javascript复制Input: 14
Output: false
Solution
代码语言:javascript复制class Solution {
public:
bool isPerfectSquare(int num) {
return int(pow(int(sqrt(num)), 2.0)) == num;
}
};