diamondpattern.java

class hollowAlphabetDiamond {
  public static void main(String[] args) {
    int size = 5;
    int alpha = 65;
    int count = 0;

    // upper pyramid
    for (int i = 1; i <= size; i++) {
      // printing spaces
      for (int j = size; j > i; j--) {
        System.out.print(" ");
      }
      // printing star
      for (int k = 0; k < i * 2 - 1; k++) {
        if (k == 0 || k == 2 * i - 2) {
          System.out.print((char)(alpha+count++));
        } else {
          System.out.print(" ");
        }
      }
      // set the number to 0
      count = 0;
      System.out.println();
    }

    // lower triangle
    for (int i = 1; i < size; i++) {
      // printing spaces
      for (int j = 0; j < i; j++) {
        System.out.print(" ");
      }
      // printing star
      for (int k = (size - i) * 2 - 1; k >= 1; k--) {
        if (k == 1 || k == (size - i) * 2 - 1) {
          System.out.print((char)(alpha+count++));
        } else {
          System.out.print(" ");
        }
      }
      // set the number to 0
      count = 0;
      System.out.println();
    }
  }
}