Power of Three (LeetCode)

Problem Description

Problem Statement	Solution Link
Power of Three	Power of Three Solution on LeetCode

Problem Description

Given an integer n, return true if it is a power of three. Otherwise, return false.

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

Examples

Example 1:

• Input: n = 27
• Output: true

Example 2:

• Input: n = 0
• Output: false

Example 3:

• Input: n = 9
• Output: true

Example 4:

• Input: n = 45
• Output: false

Constraints:

• $-2^{31} <= n <= 2^{31} - 1$

Approach

We can solve this problem by iterating and multiplying a variable starting from 3 until it exceeds or equals n. If at any point it equals n, we return true. If we exceed n without finding an exact match, we return false.

Solution Code

C++

class Solution {
public:
    bool isPowerOfThree(int n) {
        if(n == 1) {
            return true;
        }
        for(long long i = 3; i <= n; i *= 3) {
            if(i == n) {
                return true;
            }
        }
        return false;
    }
};

Python

class Solution:
    def isPowerOfThree(self, n: int) -> bool:
        if n == 1:
            return True
        i = 3
        while i <= n:
            if i == n:
                return True
            i *= 3
        return False

Java

class Solution {
    public boolean isPowerOfThree(int n) {
        if (n == 1) {
            return true;
        }
        for (long i = 3; i <= n; i *= 3) {
            if (i == n) {
                return true;
            }
        }
        return false;
    }
}

JavaScript

var isPowerOfThree = function(n) {
    if (n === 1) {
        return true;
    }
    for (let i = 3; i <= n; i *= 3) {
        if (i === n) {
            return true;
        }
    }
    return false;
};

Conclusion

The "Power of Three" problem can be solved by iteratively checking powers of three. The provided solutions in C++, Python, Java, and JavaScript efficiently implement this approach, ensuring correct results within the given constraints.