#22 C++ Programming Questions Practice : HCF of Two Numbers

Introduction

This tutorial will guide you through the process of finding the Highest Common Factor (HCF) of two numbers using C++. Understanding how to compute the HCF is essential for various mathematical applications, including simplifying fractions and finding common denominators.

Step 1: Setting Up Your C++ Environment

Before writing your code, ensure you have a C++ development environment set up. You can use any IDE like Code::Blocks, Visual Studio, or an online compiler such as repl.it.

• Install your preferred IDE or access an online compiler.
• Create a new C++ project or file.

Step 2: Writing the Function to Calculate HCF

To find the HCF of two numbers, you can implement the Euclidean algorithm. Here’s how to write the function:

1. Define a function named hcf that takes two integers as parameters.
2. Use a while loop to repeatedly apply the Euclidean algorithm until one of the numbers becomes zero.
3. Return the non-zero number as the HCF.

Here’s a sample code snippet:

#include <iostream>
using namespace std;

int hcf(int a, int b) {
    while (b != 0) {
        int temp = b;
        b = a % b;
        a = temp;
    }
    return a;
}

Step 3: Main Function to Execute the Program

Now, create the main function where you will take user inputs and display the HCF:

1. Prompt the user to enter two integers.
2. Call the hcf function with the user inputs.
3. Print the result.

Here’s how to implement it:

int main() {
    int num1, num2;
    cout << "Enter two integers: ";
    cin >> num1 >> num2;
    
    int result = hcf(num1, num2);
    cout << "The HCF of " << num1 << " and " << num2 << " is: " << result << endl;
    
    return 0;
}

Step 4: Compiling and Running the Program

Once your code is ready, follow these steps to compile and execute:

• Save your file with a .cpp extension.
• Compile your code using the build option in your IDE or using a command line:

  g++ -o hcf_program hcf_program.cpp
  

• Run the compiled program:

  ./hcf_program
  

• Input two integers when prompted to see the HCF displayed.

Conclusion

You have now successfully created a C++ program to find the HCF of two numbers using the Euclidean algorithm. This foundational concept can be expanded upon for more complex mathematical computations. Next, consider exploring other algorithms or extending this program to handle more than two numbers. Happy coding!