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1780. Check if Number is a Sum of Powers of Three

Difficulty Topics

Description

Given an integer n, return true if it is possible to represent n as the sum of distinct powers of three. Otherwise, return false.

An integer y is a power of three if there exists an integer x such that y == 3x.

 

Example 1:

Input: n = 12
Output: true
Explanation: 12 = 31 + 32

Example 2:

Input: n = 91
Output: true
Explanation: 91 = 30 + 32 + 34

Example 3:

Input: n = 21
Output: false

 

Constraints:

  • 1 <= n <= 107

Solution

check-if-number-is-a-sum-of-powers-of-three.py
class Solution:
    def checkPowersOfThree(self, n: int) -> bool:
        while n > 1:
            if n % 3 == 2: return False

            n //= 3

        return n == 1