Programa Java para imprimir el patrón de triángulo de estrella superior espejo

El patrón tiene dos partes, ambas reflejos de espejo entre sí. La base del triángulo tiene que estar en la parte inferior del espejo imaginario y la punta en la parte superior.

Ilustración:

Input:
size = 7

Output:

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

Acercarse: 

Divide el patrón en subpatrones

• divide esto en dos partes
  • Parte superior
  • Parte inferior
• Ambas partes son un reflejo de espejo el uno del otro. Y cada parte consta de 2 triángulos. Por lo tanto, en total, tenemos que imprimir 4 triángulos para obtener el patrón deseado.

Ejemplo 1: Parte Superior

// Java Program to Print Upper Part of Mirror Upper Star
// Triangle Pattern
 
// Importing input output classes
import java.io.*;
 
// Main Class
class GFG {
 
    // Method 1
    // To print upper part of the pattern
    private static void displayUpperPart(int size)
    {
 
        // Declaring variables for rows and columns
        // respectively
        int m, n;
 
        // Outer loop for rows
        for (m = size - 1; m >= 0; m--) {
 
            // Inner loop 1
            // to print triangle 1
            for (n = 0; n < m; n++) {
 
                // Printing whitespace
                System.out.print(" ");
            }
 
            // Inner loop 2
            // to print triangle 2
            for (n = m; n <= size - 1; n++) {
 
                // Printing star with whitespace
                System.out.print("*"
                                 + " ");
            }
 
            // By now done with one rpw so next line
            System.out.println();
        }
    }
 
    // Method 2
    // Main driver method
    public static void main(String[] args)
    {
        // Declaring and initializing variables to
        // size of the triangle
        int size = 7;
 
        // Calling the above Method 1 to
        // print and display the upper part of triangle
        displayUpperPart(size);
    }
}

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

Ejemplo 2: Parte inferior del triángulo 

// Java Program to Print Lower Part of Mirror Upper Star
// Triangle Pattern
 
// Importing input output classes
import java.io.*;
 
// Main Class
class GFG {
 
    // Method 1
    // To print lower part of the pattern
    private static void displayLowerPart(int size)
    {
 
        // Declaring variables for rows and columns
        // respectively
        int m, n;
 
        // Outer loop fo Rows
        for (m = 1; m <= size; m++) {
 
            // Inner loop 1 to print triangle 3
            for (n = 1; n < m; n++) {
 
                // Printing whitespace
                System.out.print(" ");
            }
 
            // Inner loop 2 to print triangle 4
            for (n = m; n <= size; n++) {
 
                // Printing star and whitespace
                System.out.print("*"
                                 + " ");
            }
 
            // By now done with one row so new line
            System.out.println();
        }
    }
 
    // Method 2
    // Main driver method
    public static void main(String[] args)
    {
        // Declaring and initializing variable to
        // size of the triangle
        // This is number of rows
        int size = 7;
 
        // Calling the above Method1
        // to display lower part of the triangle
        displayLowerPart(size);
    }
}

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

Ejemplo 3: patrón de triángulo de estrella superior de espejo completo

// Java Program to Print Mirror upper Star triangle Pattern
 
// Importing input output classes
import java.io.*;
 
// Main Class
public class GFG {
 
    // Method 1
    // To print upper part of the pattern
    private static void displayUpperPart(int size)
    {
 
        // Declaring variables for rows and columns
        // respectively
        int m, n;
 
        // Outer loop for rows
        for (m = size - 1; m >= 0; m--) {
 
            // Inner loop 1
            for (n = 0; n < m; n++) {
 
                // Printing whitespace
                System.out.print(" ");
            }
 
            // Inner loop 2
            for (n = m; n <= size - 1; n++) {
 
                // Printing star with whitespace
                System.out.print("*"
                                 + " ");
            }
 
            // By now we are done with one row so new line
            System.out.println();
        }
    }
 
    // Method 2
    // To print lower part of the pattern
    private static void displayLowerPart(int size)
    {
 
        // Declaring variables for rows and columns
        // respectively
        int m, n;
 
        // Outer loop for rows
        for (m = 1; m <= size; m++) {
 
            // Inner loop 1
            for (n = 1; n < m; n++) {
 
                // Printing whitespace
                System.out.print(" ");
            }
 
            // Inner loop 2
            for (n = m; n <= size; n++) {
 
                // Printing star and whitespace
                System.out.print("*"
                                 + " ");
            }
 
            // By now we are done with one row so new line
            System.out.println();
        }
    }
 
    // Method 3
    // Main driver method
    public static void main(String[] args)
    {
        // Declaring and initializing variable to
        // size of the triangle
        int size = 7;
 
        // Calling Method 1 to
        // display the upper part
        displayUpperPart(size);
 
        // Calling Method 2 to
        // display lower part
        displayLowerPart(size);
    }
}

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

Complejidad de tiempo : O(n ² ) donde n es el tamaño de entrada dado
Espacio auxiliar : O(1)