[LeetCode] 367. Valid Perfect Square

轉自LeetCode

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

<Solution>

因為題目有要求不能用 sqrt 來算，這時候就只能用牛頓法來算

code 如下

C++

用二分法也可以

kotlin