Question

Guided Assignment Problem 1: Multiplication

Review the Three-Question Approach used to verify the Factorial recursive algorithm in Ch. 3.2.

Your Tasks:

1. Now we need to develop a recursive algorithm for multiplication operation with two positive integers without using the multiplication operator. Your answer should be in pseudocode or Java code format.
2. Then use the Three-Question Approach to verify your recursive algorithm. No coding is required for this assignment.

   Recursive method header given as: int multiplication (int a, int b)

   Hints

3. a multiply b is to the same is b + (a -1) multiply b, in terms of recursion, the problem is simplified. The process keeps going until base case is reached, which is 1*b = b.
4. randerson112358. (2015, Feburuary 13). Recursion function to multiply two positive integers. [Video file, Length 5:13].
5. Please include the following in the Word document you created for the assignment for the final submission:
   • Your responses to the two tasks listed above

Answer 1

Code:

Code:

import java.util.Scanner;

public class Main {

// this method takes two arguments
// calculates multiplication recursive approach
// return the final result
   static int multiplication (int a, int b) {
      
//        check if the value of a is >0
// if it is greater then again call the multiplication function
       if(a>0) {
           return b + multiplication(a-1, b);
       }
      
//        else return 0
       else {
           return 0;
       }
      
   }
   public static void main(String[] args) {
      
//    declate two variables a and b
   int a,b;
  
//    create an object for scanner class
   Scanner in = new Scanner(System.in);
  
//    read the input from the user
System.out.print("Enter a value: ");
   a = in.nextInt();
  
   System.out.print("Enter b value: ");
   b = in.nextInt();
  
//    output the result by calling the multiplication(a,b)
   System.out.println(multiplication(a, b));
  
   }

}