Hollow Pyramid Star Pattern

Program to Print Hollow Pyramid Star Pattern

PRINTING PATTERN:

       *
      * *
     *   *
    *******
            

PREREQUISITE:

Basic knowledge of Java language and loops.

ALGORITHM:

1. Take the number of rows as input from the user (height of the pyramid) and store it in a variable ('n').
2. Run a loop 'n' times to iterate through the rows (i=1 to i<=n).
3. For each row, print spaces to create the left alignment of the stars.
4. For the first and last rows, print stars for the entire row.
5. For the rows in between, print a star at the beginning and end, and spaces in between.
6. Move to the next line after each row has been printed.

Code in Java:

import java.util.Scanner;

public class HollowPyramidPattern {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        System.out.println("Enter the number of rows for the hollow pyramid:");
        int n = scanner.nextInt();  // Taking input for number of rows

        for (int i = 1; i <= n; i++) {
            // Print spaces for pyramid shape
            for (int j = n - i; j > 0; j--) {
                System.out.print(" ");  // Printing spaces
            }
            // Print stars for each row
            for (int j = 1; j <= (2 * i - 1); j++) {
                // Print '*' for the first and last row, and first and last column
                if (i == n || j == 1 || j == (2 * i - 1)) {
                    System.out.print("*");  // Printing stars
                } else {
                    System.out.print(" ");  // Printing spaces for hollow part
                }
            }
            System.out.println();  // New line after each row
        }

        scanner.close();
    }
}
            

Output:

Enter the number of rows for the hollow pyramid:
4
       *
      * *
     *   *
    *******