Patterns

Right Triangle

class Solution {
    public void printRightTriangle(int n) {
        for (int i = 1; i <= n; i++) {
            for (int j = 1; j <= i; j++) System.out.print("* ");
            System.out.println();
        }
    }
}

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

---

Inverted Right Triangle

class Solution {
    public void printInvertedRightTriangle(int n) {
        for (int i = n; i >= 1; i--) {
            for (int j = 1; j <= i; j++) System.out.print("* ");
            System.out.println();
        }
    }
}

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

---

Left Triangle

class Solution {
    public void printLeftTriangle(int n) {
        for (int i = 1; i <= n; i++) {
            for (int j = 1; j <= n - i; j++) System.out.print("  ");
            for (int k = 1; k <= i; k++) System.out.print("* ");
            System.out.println();
        }
    }
}

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

---

Pyramid

class Solution {
    public void printPyramid(int n) {
        for (int i = 1; i <= n; i++) {
            for (int j = 1; j <= n - i; j++) System.out.print(" ");
            for (int k = 1; k <= 2 * i - 1; k++) System.out.print("*");
            System.out.println();
        }
    }
}

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

---

Inverted Pyramid

class Solution {
    public void printInvertedPyramid(int n) {
        for (int i = n; i >= 1; i--) {
            for (int j = 1; j <= n - i; j++) System.out.print(" ");
            for (int k = 1; k <= 2 * i - 1; k++) System.out.print("*");
            System.out.println();
        }
    }
}

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

---

Diamond

class Solution {
    public void printDiamond(int n) {
        for (int i = 1; i <= n; i++) {
            for (int j = 1; j <= n - i; j++) System.out.print(" ");
            for (int k = 1; k <= 2 * i - 1; k++) System.out.print("*");
            System.out.println();
        }
        for (int i = n - 1; i >= 1; i--) {
            for (int j = 1; j <= n - i; j++) System.out.print(" ");
            for (int k = 1; k <= 2 * i - 1; k++) System.out.print("*");
            System.out.println();
        }
    }
}

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

---

Opposite Zero and One

class Main {
    public static void main(String[] args) {
        int n = 4;
        for (int i = 1; i <= n; i++) {
            for (int j = 1; j <= i; j++) {
                System.out.print((i + j) % 2 + " ");
            }
            System.out.println();
        }
    }
}

0
1 0
0 1 0
1 0 1 0

---

Diagonal Cross (Both Diagonals)

class Main {
    public static void main(String[] args) {
        int n = 5;
        for (int i = 1; i <= n; i++) {
            for (int j = 1; j <= n; j++) {
                if (i == j || i + j == n + 1) System.out.print("* ");
                else System.out.print("  ");
            }
            System.out.println();
        }
    }
}

*       *
  *   *
    *
  *   *
*       *

---

Diagonal Numbers

class Main {
    public static void main(String[] args) {
        int n = 4;
        for (int i = 1; i <= n; i++) {
            for (int j = 1; j <= n; j++) {
                if (i == j) System.out.print(i + " ");
                else System.out.print("  ");
            }
            System.out.println();
        }
    }
}

1
  2
    3
      4

---

Diagonal Cross Numbers

class Main {
    public static void main(String[] args) {
        int n = 5;
        for (int i = 1; i <= n; i++) {
            for (int j = 1; j <= n; j++) {
                if (i == j || i + j == n + 1) System.out.print(i + " ");
                else System.out.print("  ");
            }
            System.out.println();
        }
    }
}

1       1
  2   2
    3
  4   4
5       5