Hold住Leetcode

Given a positive integer num, write a function which returns True if num is a perfect square else False.

判断输入的值是不是平方值，不能用sqrt()函数

Example 1:

Input: 16
Returns: True

Example 2:

Input: 14
Returns: False

class Solution {
public:
    bool isPerfectSquare(int num) {
      return  int(pow(num,0.5))==pow(num,0.5)?true:false;//pow()为求某个数的某次幂
    }
};

class Solution {
public:
    bool isPerfectSquare(int num) {
     for(int i=1;i<=num/i;i++)
     {if(i*i==num)
     return true;}
     return false;
     
    }
};