Pattern Program

/********************************************************************

 *i wrote this program when one great person was sitting with me :-)* 

 ********************************************************************/



/*

Output:

Enter an Odd number : 5



 * * * * *

 *   *   *

 * *   * *

 *   *   *

 * * * * *



 */

// you can also do the same program using 3 loops



/*

 * No negative inputs please

 */

/**

 * A quote: there are more than one ways to do it

 */

package javaapplication2;



import java.util.Scanner;



/**

 *

 * @author Umang

 */

public class Main

{

    /**

     * @param args the command line arguments

     */

    public static void main(String[] args)

    {

        boolean b = false;



        // to print inner stars

        int n1 = 0;

        int n2 = 0;

        // n1 and n2 indicate in which column the inner stars should be

        // placed.

        // in each iteration (of outer loop), the value of

        // these two variables are changed



        // loop variables

        int j = 0, k = 0;



        Scanner s = new Scanner(System.in);



        System.out.print("Enter an Odd number : ");

        int n = s.nextInt();



        n1 = n2 = n / 2;



        System.out.print("\n");



        for (j = 0; j < n; j++)

        {

            for (k = 0; k < n; k++)

            {

                // if it is first or last line then print only *

                // no spaces in first and last line

                if (j == 0 || j == n - 1)

                {

                    System.out.print(" * ");

                }

                else

                {

                    // we come here if it is not first or last line



                    // n1 and n2 are the variables that hold informatin regarding where

                    // we want to print inner *s



                    // print * if it is the first or last column

                    // or the column value = n1 or n2

                    if (k == n1 || k == n2 || k == 0 || k == n - 1)

                    {

                        System.out.print(" * ");

                    }

                    else

                    {

                        // print blank space

                        System.out.print("   ");

                    }

                }

            }

            // prnit new line


            System.out.println();



            // now change the place of inner *s

           

            // this if changes the increment decrement pattern

            if (j == (n / 2))

            {

                // if j == n / 2 then we need to change the pattern

                // in which the numbers are incrementd



                // b is a flag variable

                b = true;

            }

            if (j != 0 && j != n - 1)

            {

                if (b == false)

                {

                    // we come here if we are in first upper part of pattern

                    n1--;

                    n2++;

                }

                else

                {

                    // we come here if we are in lower part of pattern


                    n1++;

                    n2--;

                }

            }

        }

        System.out.print("\n");

    }

}