GCD of Two Numbers

Program to find Greatest Common Divisor using Euclidean algorithm

IntermediateTopic: Loop Programs
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C++ GCD of Two Numbers Program

This program helps you to learn the fundamental structure and syntax of C++ programming.

Try This Code
#include <iostream>
using namespace std;

int main() {
    int a, b, temp;
    
    cout << "Enter two numbers: ";
    cin >> a >> b;
    
    int originalA = a, originalB = b;
    
    // Euclidean algorithm
    while (b != 0) {
        temp = b;
        b = a % b;
        a = temp;
    }
    
    cout << "GCD of " << originalA << " and " << originalB << " is: " << a << endl;
    
    return 0;
}
Output
Enter two numbers: 48 18
GCD of 48 and 18 is: 6

Understanding GCD of Two Numbers

The Euclidean algorithm finds GCD by repeatedly applying: GCD(a, b) = GCD(b, a % b) until b becomes 0. The GCD is then the value of a. This is an efficient method that works for any two positive integers.

Note: To write and run C++ programs, you need to set up the local environment on your computer. Refer to the complete article Setting up C++ Development Environment. If you do not want to set up the local environment on your computer, you can also use online IDE to write and run your C++ programs.

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