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

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

Solutions

Solution 1

Python Code
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class Solution:
    def checkPowersOfThree(self, n: int) -> bool:
        while n:
            if n % 3 > 1:
                return False
            n //= 3
        return True

Java Code
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class Solution {
    public boolean checkPowersOfThree(int n) {
        while (n > 0) {
            if (n % 3 > 1) {
                return false;
            }
            n /= 3;
        }
        return true;
    }
}

C++ Code
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class Solution {
public:
    bool checkPowersOfThree(int n) {
        while (n) {
            if (n % 3 > 1) return false;
            n /= 3;
        }
        return true;
    }
};

Go Code
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func checkPowersOfThree(n int) bool {
	for n > 0 {
		if n%3 > 1 {
			return false
		}
		n /= 3
	}
	return true
}

TypeScript Code
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function checkPowersOfThree(n: number): boolean {
    while (n) {
        if (n % 3 > 1) return false;
        n = Math.floor(n / 3);
    }
    return true;
}