(Greatest Common Divisor ) Given two integers x and y, the following recursive definition...

(Greatest Common Divisor ) Given two integers x and y, the following recursive definition determines the greatest common divisor of x and y , written gcd(x, y):

Note: In this definition, % is the mod operator.

Write a recursive function, gcd , that takes as parameters two integers and returns the greatest common divisor of the numbers. Also, write a program to test your function.