Python Program to Check Power of 3

Posted in Python Tutorial

Updated on Jan 11, 2024

By Mari Selvan

👁️ 81 - Views

⏳ 4 mins

💬 1 Comment

Photo Credit to CodeToFun

🙋 Introduction

In the realm of programming, one often encounters the need to check if a given number is a power of another.

In this context, we'll explore a Python program designed specifically to check if a number is a power of 3.

The logic behind this program involves repeatedly dividing the number by 3 until it becomes 1, indicating that it is a power of 3.

📄 Example

Let's delve into the Python code that achieves this functionality.

is_power_of_3.py

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# Function to check if a number is a power of 3
def is_power_of_3(n):
    # Keep dividing the number by 3 until it is greater than 1
    while n % 3 == 0 and n > 1:
        n //= 3

    # If the final value is 1, the original number is a power of 3
    return n == 1

# Driver program
if __name__ == "__main__":
    # Replace this value with your desired number
    number = 27

    # Check if the number is a power of 3
    if is_power_of_3(number):
        print(f"{number} is a power of 3")
    else:
        print(f"{number} is not a power of 3")

💻 Testing the Program

To test the program with different numbers, simply replace the value of number in the if __name__ == "__main__": block.

Output

27 is a power of 3

Run the script to see if the given number is a power of 3.

🧠 How the Program Works

The program defines a function is_power_of_3 that takes an integer as input and checks if it is a power of 3.
Inside the function, it repeatedly divides the number by 3 until it becomes greater than 1.
If the final value is 1, the original number is a power of 3, and the function returns True; otherwise, it returns False.
The driver program in the if __name__ == "__main__": block tests a specific number and prints whether it is a power of 3 or not.

📏 Between the Given Range

Let's take a look at the python code that checks for powers of 3 in the given range.

is_power_of_three.py

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# Function to check if a number is a power of 3
def is_power_of_three(num):
    return num > 0 and (3 ** 19) % num == 0

# Display powers of 3 in the range 1 to 20
def display_powers_of_three():
    print("Power of 3 in the range 1 to 20:")

    for i in range(1, 21):
        if is_power_of_three(i):
            print(i, end=" ")

# Driver program
if __name__ == "__main__":
    # Call the function to display powers of 3
    display_powers_of_three()

💻 Testing the Program

Output

Power of 3 in the range 1 to 20:
1 3 9

Run the script to see the powers of 3 in the range from 1 to 20.

🧠 How the Program Works

The program defines a function is_power_of_three that checks if a number is a power of 3 using the property that 3¹⁹ is the largest power of 3 that fits within the 32-bit signed integer range.
The display_powers_of_three function iterates through the range from 1 to 20 and prints the numbers that are powers of 3.
The main block calls the function to display the powers of 3 in the specified range.

🧐 Understanding the Concept of Power of 3

Before diving into the code, let's understand the concept of a power of 3.

A number is considered a power of 3 if it can be expressed as 3^n, where n is an integer.

For example, 1, 3, 9, 27, and so on are powers of 3.

🎢 Optimizing the Program

While the provided program is straightforward, there are alternative approaches to check if a number is a power of 3. Consider exploring other mathematical techniques for optimization.

Feel free to incorporate and modify this code as needed for your specific use case. Happy coding!