Step-by-Step Guide to Finding GCD in C++

1. Structure of a C++ Program

Every C++ program follows a basic structure:

#include <iostream>
using namespace std;

int main() {
    // Code goes here
    return 0;
}

2. Reading Two Numbers from the Keyboard

To take user input in C++:

#include <iostream>
using namespace std;

int main() {
    int a, b;
    cout << "Enter two numbers: ";
    cin >> a >> b;
    cout << "You entered: " << a << " and " << b << endl;
    return 0;
}

3. Pseudocode for Finding GCD

Before writing the code, let's outline the logic using pseudocode:

Function gcd(a, b):
    While b ≠ 0:
        temp = b
        b = a % b
        a = temp
    Return a

4. Optimizing the GCD Calculation

To improve efficiency:

Use the Euclidean Algorithm for efficient computation.
Iterate using modulus instead of subtraction.

5. Full Optimized Program

Final step involves implementing the optimized approach in C++.