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Calculate Product of Two Numbers Using Sums 'Iterative and Recursive' in C#

In this exercise, you are required to write two functions in C#. Both functions will calculate the product of two numbers, but the methods used will be different. The first function, Multiply, will use an iterative approach, while the second function, MultiplyR, will use recursion to achieve the same result. Both functions will simulate multiplication by repeatedly adding one number to itself. This will help you understand the underlying mechanism of multiplication using addition.



Group

Functions in C#

Objective

1. Write the Multiply function using an iterative approach.
2. Write the MultiplyR function using a recursive approach.
3. Both functions should calculate the product of two numbers by adding the first number repeatedly the number of times specified by the second number.
4. Test both functions with sample inputs to verify their correctness.

Write two C# functions, Multiply and MultiplyR, to calculate the product of two numbers using sums. The first version must be iterative, and the second one must be recursive.

Example: 

Multiply(3, 4);    // Output should be 12

MultiplyR(3, 4);   // Output should be 12

Example C# Exercise

 Copy C# Code 
using System;

class Program
{
    // Iterative version of Multiply function
    static int Multiply(int a, int b)
    {
        int result = 0;  // Initialize result to 0
        
        // Add 'a' to the result 'b' times
        for (int i = 0; i < b; i++)
        {
            result += a;  // Add 'a' to result in each iteration
        }
        
        return result;  // Return the final result
    }

    // Recursive version of Multiply function
    static int MultiplyR(int a, int b)
    {
        // Base case: if b is 0, return 0 (any number multiplied by 0 is 0)
        if (b == 0)
        {
            return 0;
        }
        
        // Recursive case: add 'a' to the result of MultiplyR with 'b-1'
        return a + MultiplyR(a, b - 1);
    }

    static void Main()
    {
        int result1 = Multiply(3, 4);  // Call the iterative Multiply function
        Console.WriteLine("Iterative Multiply: " + result1);  // Output the result
        
        int result2 = MultiplyR(3, 4); // Call the recursive MultiplyR function
        Console.WriteLine("Recursive Multiply: " + result2); // Output the result
    }
}

 Output

Iterative Multiply: 12
Recursive Multiply: 12

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