326. Power of Three

    这考的是数学基础

    1. class Solution {
    2.     public boolean isPowerOfThree(int n) {
    4.         if(n <= 0) {
    5.             return false;
    6.         }
    8.         while( n % 3 == 0 ) {
    9.             n = n / 3;
    10.         }
    12.         return n == 1;
    14.     }
    15. }