# Question

Formatted question description: https://leetcode.ca/all/367.html

```
367 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
```

# Algorithm

Search from 1 to sqrt(num) to see if there is a number whose square is exactly equal to num.

# Code

Java