leetcode-326-Power of Three

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

Follow up:

Could you do it without using any loop / recursion?

Credits:

Special thanks to @dietpepsi for adding this problem and creating all test cases.

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判断一个数是否为3的次方
C++

class Solution {
public:
bool isPowerOfThree(int n) {
if ( !n ) return false ;
while ( n != 1 ) {
if ( n % 3 ) return false ;
else n = n / 3 ;
}
return true ;
}
};

python

class Solution(object):
def isPowerOfThree(self, n):
"""
:type n: int
:rtype: bool
"""
if n == 0 :
return False
while n != 1 :
if ( n % 3 != 0 ) : return False
else : n = n / 3 ;

return True