367. Valid Perfect Square[E]

https://leetcode.com/problems/valid-perfect-square/

Description

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

Follow up: Do not use any built-in library function such as sqrt.

Example 1:

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Input: num = 16
Output: true

Example 2:

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Input: num = 14
Output: false

Constraints:

  • 1 <= num <= 2^31 - 1

Solution

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