Practical 3 and 4

Pactical-3

Find out Prime-Palindrome numbers between 1 to 10,000.

public class PalindromicPrime

{

    public static void main(String[] args)

    {

                                final int total = 100;

                                final int displayPerLine = 10;

                                int count = 1;

                                int number = 2;

                                while (count <= total)

                                {

                                                  if (isPrime(number) && isPalindrome(number))

                                                  {

                                                     System.out.print(number + " ");

                                                     if (count % displayPerLine == 0)

                                                                 System.out.println();

                                                     count++;

                                                  }  

                                                  number++;

                                }

                }

       public static boolean isPrime(int num)

    {

                if (num == 2)

                   return true;

                for (int divisor = 2; divisor <= num/2; divisor++)

                {

                                if (num % divisor == 0)

                                   return false;

                }

                return true;

    }

    public static int reverse(int num)

    {

                int test = 0;

                while (num != 0)

                {

                                  int lastdigit = num % 10;

                                  test = test * 10 + lastdigit;

                                  num = num / 10;

                }

                return test;

    }

    public static boolean isPalindrome(int num)

    {

                return num == reverse(num);

    }

}

Practical-4

Display output of series 1/1!-1/2! +1/3!-1/4!+1/5!...

class series2

{

    public static void main(String args[])

    {

        int n,i;

        n=5;

        double S=0,f=0;

        for(i=1;i<n;i++)

        {      if(i%2==0)                          
         {
              f=fact(i);   
             S=S-(1/f);
          }

            f=fact(i);            S=S+(1/f);

        }        System.out.println("The sum ="+S);

    }

        public static double fact(int num)

    {

        int f=1,j;

        for(j=1;j<=num;j++)

        {

            f=f*j;

        }

        return(f);

    }  }