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Ruby program to find the HCF of two given numbers using recursion

Last Updated : December 15, 2025

Problem Solution

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

Program/Source Code

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

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

def calculateHCF(a, b)
    while a != b
        if a > b
            return calculateHCF(a - b, b);
        else
            return calculateHCF(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 = calculateHCF(number1, number2);

print "HCF is: ",result;

Output

Enter number1: 36
Enter number2: 48
HCF is: 12

Explanation

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

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