Q. Write a program to check if a given number is a power of three or not.

We are provided with a number as input and we need to check if the given number is a power of three or not.

For Example :-
n = 81
Output = Yes, 81 is a power of 3. (3^4 = 81)

Algorithm

To solve this problem, we can use the following algorithm:

START
Step 1 : Check if number is divisible by zero or not. If it return False then zero is not power of 3.

Step 2 : If number if divisible by 3 then keep dividing the number by 3 until it is no longer divisible by three.

Step 3 : After the loop end check if remaining number is 1 or not. If the remaining number is 1 then the number is a power of three.
STOP

Program to check if a given number is a power of three or not

C++

Java

Python

#include <stdio.h>

int main() {
    int num;
    printf("Enter a number: ");
    scanf("%d", &num);
    
    while (num > 1) {
        if (num % 3 != 0) {
            printf("%d is not a power of three.\n", num);
            return 0;
        }
        num = num / 3;
    }
    printf("%d is a power of three.\n", num);
    return 0;
}

#include <iostream>
using namespace std;

bool isPowerOfThree(int n) {
    if (n <= 0) {
        return false;
    }
    while (n % 3 == 0) {
        n /= 3;
    }
    return n == 1;
}

int main() {
    int n;
    cout << "Enter a number: ";
    cin >> n;
    if (isPowerOfThree(n)) {
        cout << n << " is a power of 3\n";
    } else {
        cout << n << " is not a power of 3\n";
    }
    return 0;
}

public class PowerOfThree {
    public static boolean isPowerOfThree(int n) {
        if (n <= 0) {
            return false;
        }
        while (n % 3 == 0) {
            n /= 3;
        }
        return n == 1;
    }

    public static void main(String[] args) {
        int n = 27;
        if (isPowerOfThree(n)) {
            System.out.println(n + " is a power of three");
        } else {
            System.out.println(n + " is not a power of three");
        }
    }
}

def isPowerOfThree(n):
    if n <= 0:
        return False
    while n % 3 == 0:
        n = n // 3
    return n == 1

using System;

public class Program {
    public static bool IsPowerOfThree(int n) {
        if (n <= 0) {
            return false;
        }

        while (n > 1) {
            if (n % 3 != 0) {
                return false;
            }

            n /= 3;
        }

        return true;
    }

    public static void Main() {
        int num = 27;
        if (IsPowerOfThree(num)) {
            Console.WriteLine($"{num} is a power of three");
        } else {
            Console.WriteLine($"{num} is not a power of three");
        }
    }
}

#include <stdio.h>

int main() {
    int num;
    printf("Enter a number: ");
    scanf("%d", &num);
    
    while (num > 1) {
        if (num % 3 != 0) {
            printf("%d is not a power of three.\n", num);
            return 0;
        }
        num = num / 3;
    }
    printf("%d is a power of three.\n", num);
    return 0;
}

Output

27 is a power of three.

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