GCD using Euclid’s algorithm

Hello, I am having trouble with this homework question for my intro to C++

1.Write a recursive function calculate GCD using Euclid’s algorithm.

a. Request input values for a and b from the console.
b. The function accepts integers a and b as input parameters.
c. The function returns the GCD of a and b using Euclid’s algorithm.
d. Add a print statement to display the process (see example output).
e. Trace the recursive process for this function.
Euclid’s GCD Algorithm:
a) GCD(a,b) = GCD(b, a mod b)
b) GCD(a, 0) = a
Recall the process of thinking recursively.
a) Determine the repetitive steps (recursive task).
b) Determine a condition to end the repetition (base case).

Output Example

Enter two positive integers: 20 16
20 16
16 4
4 0
4