[LeetCode] Power of Three | Power of Two

[LeetCode] Power of Three | Power of Two

Given an integer, write a function to determine if it is a power of three.

Follow up:
Cocould you do it without using any loop/recursion?

Solutions

Log operation.

Implementation Code

// Runtime: 18 mspublic class Solution {public boolean isPowerOfThree (int n) {double res = Math. log (n)/Math. log (3); return Math. abs (res-Math. round (res) <1e-10 ;}}

Given an integer, write a function to determine if it is a power of two.

Solutions

The Npower of 2 must be greater than 0, and only one of the binary bits is 1.

Implementation Code

Public class Solution {public boolean isPowerOfTwo (int n) {return n> 0 & (n & n-1) = 0 ;}}