Question

Java

Create a new Drive class.

* Create a Menu class.

* The menu class will use the previous 4 classes you created in GCD, LCM, FACTORIAL, DIGITS

The Menu will display a menu that give you the option of selecting:

1) Greatest Common Denominator

2) Lowest Common Multiple

3) Factorial

4) Number of Digits in an Integer

Enter 1,2,3 or 4:

When the User enter the choice,

then the correct function/method is called for the class and

asks the user for input(s) to use.

The system will then display the results.

Run your code and Test with the following values:

1) 144

2) 42

3) 5

4) 987654321

Create UML diagrams for your classes.

Answer 1

import java.util.Scanner;
import java.util.Vector;
public class Drive {
        
         static void count(int num) {
                int count = 0;

        while(num != 0)
        {
            num /= 10;
            ++count;
        }
        
        System.out.println("Number of digits: " + count);
    }
        
        static int gcd(int a, int b) 
    { 
        if (a == 0) 
            return b; 
        return gcd(b % a, a); 
    } 
        static void findGCD(int arr[], int n) 
    { 
        int result = arr[0]; 
        for (int i = 1; i < n; i++) 
            result = gcd(arr[i], result); 
  
        System.out.printf("GCD is: %d", result); 
    } 
        
        public static void factorial(int num){
                
        long factorial = 1;
        for(int i = 1; i <= num; ++i)
        {
            // factorial = factorial * i;
            factorial *= i;
        }
        System.out.printf("Factorial of %d = %d", num, factorial);   
        }  
        
        static long LCM(int arr[], int n) { 

        int max_num = 0; 
        for (int i = 0; i < n; i++) { 
            if (max_num < arr[i]) { 
                max_num = arr[i]; 
            } 
        } 
  
        // Initialize result  
        long res = 1; 
  
        // Find all factors that are present in  
        // two or more array elements.  
        int x = 2; // Current factor.  
        while (x <= max_num) { 
            // To store indexes of all array  
            // elements that are divisible by x.  
            Vector<Integer> indexes = new Vector<>(); 
            for (int j = 0; j < n; j++) { 
                if (arr[j] % x == 0) { 
                    indexes.add(indexes.size(), j); 
                } 
            } 
  
            // If there are 2 or more array elements  
            // that are divisible by x.  
            if (indexes.size() >= 2) { 
                // Reduce all array elements divisible  
                // by x.  
                for (int j = 0; j < indexes.size(); j++) { 
                    arr[indexes.get(j)] = arr[indexes.get(j)] / x; 
                } 
  
                res = res * x; 
            } else { 
                x++; 
            } 
        } 
  
        // Then multiply all reduced array elements  
        for (int i = 0; i < n; i++) { 
            res = res * arr[i]; 
        } 
  
        return res; 
    } 
        
        public static void main(String[] args) {
                
                Scanner sc = new Scanner(System.in);
                int ch, n, i;
                
                while(true) {
                        System.out.println("Menu: ");
                        System.out.println("1) Greatest Common Denominator");
                        System.out.println("2) Lowest Common Multiple");
                        System.out.println("3) Factorial");
                        System.out.println("4) Number of Digits in an Integer");
                        System.out.println("Enter your choice: ");
                        
                        ch = sc.nextInt();
                        switch(ch) {
                        case 1:
                                System.out.println("How many numbers do you want to input: ");
                                n = sc.nextInt();
                                int[] arr = new int[20];
                                System.out.println("Enter the numbers: ");
                                for(i = 0; i < n; i++) {
                                        arr[i] = sc.nextInt();  
                                }
                                findGCD(arr, n);
                                break;
                        case 2:
                                System.out.println("How many numbers you want to input: ");
                                n = sc.nextInt();
                                int[] a = new int[20];
                                System.out.println("Enter the numbers: ");
                                for(i = 0; i < n; i++) {
                                        a[i] = sc.nextInt();    
                                }
                                System.out.println(LCM(a, n));
                                break;
                        case 3:
                                System.out.println("Enter the number you want to find the factorial of: ");
                                n = sc.nextInt();
                                factorial(n);
                                break;
                        case 4:
                                System.out.println("Enter integer: ");
                                n = sc.nextInt();
                                count(n);
                                break;
                        default: break;
                        }
                        
                        
                }
        }
}