Answer to Question #180890 in C++ for Darren

Question

Write a function named "g_c_d" that takes two positive integer arguments and returns as its value the greatest common divisor of those two integers. If the function passed an argument that is not positive (less than zero), then the function should return the value 0 as a sentinel value to indicate that an error occurred.

         cout << g_c_d(40,50) << endl;  

         cout << g_c_d(256,625) << endl; 

        cout << g_c_d(42,6) << endl;     

        cout << g_c_d(0,32) << endl;     

       cout << g_c_d(10,-6) << endl;   

Answer 1

#include <iostream>
#include <algorithm> // swap

int g_c_d(int x, int y) {
    if(x < 0 || y < 0) return 0;
    while(x && y) {
        x %= y;
        std::swap(x, y);
    }
    return x + y;
}

int main() {
    using std::cout;
    using std::endl;
    cout << g_c_d(40,50) << endl;  
    cout << g_c_d(256,625) << endl; 
    cout << g_c_d(42,6) << endl;     
    cout << g_c_d(0,32) << endl;     
    cout << g_c_d(10,-6) << endl;   
    return 0;
}