[LeetCode]326. Power of Three ★

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Title Description

Given an integer, write a function to determine if it is a power of three.
Title effect: Given an integer, it is determined whether the integer. 3
n-th power

Sample

Example 1:

Input: 27
Output: true

Example 2:

Input: 0
Output: false

Example 3:

Input: 9
Output: true

Example 4:

Input: 45
Output: false

python Solution

class Solution:
    def isPowerOfThree(self, n: int) -> bool:
        return n>0 and 1162261467 % n == 0

Runtime: 96 MS
Memory Usage: 13.9 MB
title after reflection:

1. This should be the easiest way to write, but not the fastest wording.
2. 1162261467 is the greatest integer 32-bit signed integer 3 inside the acceptable power.

C language Solution

bool isPowerOfThree(int n){
    return n>0?1162261467 % n == 0:false;
}

Runtime: 12 ms, faster than 82.84% of C online submissions for Power of Three.
Memory Usage: 7.5 MB, less than 50.00% of C online submissions for Power of Three.
题后反思：无

bool isPowerOfThree(int n){
    while(n>2)
    {
        if (n%3)
            return false;
        n /= 3;
    }
    return n == 1;
}

Runtime: 24 ms
Memory Usage: 7.5 MB

This paper is my personal understanding, if the wrong place welcome comments below tell me, I promptly corrected, common progress