# Ruby program to find the GCD of two given numbers using recursion

Ruby Example: Write a program to find the GCD of two given numbers using recursion.
Submitted by Nidhi, on December 25, 2021

Problem Solution:

In this program, we will read two integer numbers from the user and find the GCD of input numbers using recursion.

Program/Source Code:

The source code to find the GCD of two given numbers using recursion is given below. The given program is compiled and executed successfully.

```# Ruby program to find the GCD of
# two given numbers using recursion

def calculateGCD(a, b)
while (a != b)
if a > b
return calculateGCD(a - b, b);
else
return calculateGCD(a, b - a);
end
end

return a;
end

print "Enter number1: ";
number1 = gets.chomp.to_i;

print "Enter number2: ";
number2 = gets.chomp.to_i;

result = calculateGCD(number1, number2);

print "GCD is: ",result;
```

Output:

```Enter number1: 45
Enter number2: 75
GCD is: 15
```

Explanation:

In the above program, we read two integer numbers from the user. Then we found the GCD of input numbers using recursive function calculateGCD(). Then we printed the result.