Question

Using switch case write a menu driven program to accept a number and print whether is it an
Armstrong number or an exact number.
Armstrong Number: If the sum of the cube of the digits of a number is the number itself.

Example: 371=33+73+13= 27+343+1=371
Exact Number: if the sum of the factorial of the numbers is the number itself. Example: 145= 1! + 4! + 5! = 1 + 24 + 120 = 145

Answer 1

Program:-

import java.util.*;

public class MenuDriven

{

public static void main(String args[ ])

{

Scanner in=new Scanner(System.in);

int ch;

System.out.println("Enter 1 to check whether a number is Armstrong or not");

System.out.println("Enter 2 for checking whether a number is an exact number or not");

System.out.println("Enter your choice");

ch=in.nextInt();

switch(ch)

{

case 1:

int n,num=0,a=0,s=0;

System.out.println("Enter the number");

n=in.nextInt();

while(n!=0)

{

a=n%10;

s=s+a*a*a;

n=n/10;

}

if(s==num)

System.out.println("It is an Armstrong number");

else

System.out.println("It is not an Armstrong number");

break;

case 2:

int n1,r=0,fact=1,num1=0;

System.out.println("Enter the number");

n1=in.nextInt();

num1=n1;

while(n1!=0)

{

r=n%10;

for(int i=1;i<=r;i++)

{

fact=fact*i;

sum=sum+fact;

}

n=n/10;

}

if(sum==num1)

System.out.println("It is an exact number");

else

System.out.println("It is not an exact number");

break;

default:

System.out.println("Wrong choice");

}

}

}