Lab3.java

import static java.lang.Math.max; 
import java.util.Scanner;

public class Lab3 {
    //Q2
    static int Multiply(int a, int b){
        if(a<10 || b<10){
            return (a*b);
        }

        int n=Math.max(Integer.toString(a).length(),Integer.toString(b).length());
        int mid=n/2;

        int high1=(int)(a/Math.pow(10,mid));
        int low1=(int)(a%Math.pow(10,mid));
        int high2=(int)(b/Math.pow(10,mid));
        int low2=(int)(b%Math.pow(10,mid));

        int highs=Multiply(high1,high2);
        int mids=Multiply((high1+low1),(high2+low2));
        int lows=Multiply(low1,low2);

        int result=highs*(int)Math.pow(10,2*mid)+(mids-highs-lows)*(int)Math.pow(10,mid)+lows;
        
        return(result);
    

    }

    public static void main(String[] args) {
        int num1,num2;
        Scanner sc=new Scanner(System.in);
        System.out.println("Enter the number");
        num1=sc.nextInt();
        System.out.println("Enter the number");
        num2=sc.nextInt();
        int product=Multiply(num1, num2);
        System.out.println("The product is"+" "+product);
    }
    
}