LeetCode: Valid Perfect Square

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

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