Pattern Program Questions in Java

Pattern Program Questions in Java

Here’s a structured set of pattern-programming problems in Java, formatted as individual problem statements with explanations and diagrams


Pattern Program Problems in Java

  1. Square Star Pattern

    Problem Statement: Write a Java program to print a square star pattern of size n.

    Example (for ( n = 5 )):

     *****
     *****
     *****
     *****
     *****
    
  2. Right Triangle Star Pattern

    Problem Statement: Write a Java program to print a right triangle star pattern of height n.

    Example (for ( n = 5 )):

     *
     **
     ***
     ****
     *****
    
  3. Inverted Right Triangle Star Pattern

    Problem Statement: Write a Java program to print an inverted right triangle star pattern of height n.

    Example (for ( n = 5 )):

     *****
     ****
     ***
     **
     *
    
  4. Pyramid Star Pattern

    Problem Statement: Write a Java program to print a centered pyramid pattern of height n.

    Example (for ( n = 5 )):

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

    Hint: Use spaces for alignment.

  5. Inverted Pyramid Star Pattern

    Problem Statement: Write a Java program to print an inverted centered pyramid pattern of height n.

    Example (for ( n = 5 )):

     *********
      *******
       *****
        ***
         *
    
  6. Hollow Pyramid Star Pattern

    Problem Statement: Write a Java program to print a hollow pyramid of height n.

    Example (for ( n = 5 )):

         *
        * *
       *   *
      *     *
     *********
    
  7. Diamond Star Pattern

    Problem Statement: Write a Java program to print a diamond star pattern of height n. The diamond should have 2*n - 1 rows in total.

    Example (for ( n = 5 )):

         *
        ***
       *****
      *******
     *********
      *******
       *****
        ***
         *
    
  8. Hollow Diamond Star Pattern

    Problem Statement: Write a Java program to print a hollow diamond star pattern of height n.

    Example (for ( n = 5 )):

         *
        * *
       *   *
      *     *
     *       *
      *     *
       *   *
        * *
         *
    
  9. Right Triangle Number Pattern

    Problem Statement: Write a Java program to print a right triangle number pattern up to n rows.

    Example (for ( n = 5 )):

     1
     12
     123
     1234
     12345
    
  10. Pyramid Number Pattern

    Problem Statement: Write a Java program to print a centered pyramid pattern with numbers. Each row should display numbers in increasing order starting from 1.

    Example (for ( n = 5 )):

        1
       1 2
      1 2 3
     1 2 3 4
    1 2 3 4 5
    
  11. Pascal's Triangle

    Problem Statement: Write a Java program to print Pascal's Triangle of height n.

    Example (for ( n = 5 )):

           1
          1 1
         1 2 1
        1 3 3 1
       1 4 6 4 1
    

    Hint: Use the combination formula ( C(n, k) = \frac{n!}{k!(n-k)!} ).

  12. Floyd’s Triangle

    Problem Statement: Write a Java program to print Floyd's Triangle of height n.

    Example (for ( n = 5 )):

    1
    2 3
    4 5 6
    7 8 9 10
    11 12 13 14 15
    
  13. Square Number Pattern

    Problem Statement: Write a Java program to print a square number pattern with numbers from 1 to n. Each row should start from the first number of the sequence.

    Example (for ( n = 4 )):

    1 2 3 4
    5 6 7 8
    9 10 11 12
    13 14 15 16
    
  14. Hollow Square Pattern with Border

    Problem Statement: Write a Java program to print a hollow square pattern of size n, with a border of stars.

    Example (for ( n = 5 )):

    *****
    *   *
    *   *
    *   *
    *****
    
  15. Zigzag Number Pattern

    Problem Statement: Write a Java program to print a zigzag number pattern of height n, with numbers increasing row by row.

    Example (for ( n = 5 )):

    1
    2 3
    6 5 4
    7 8 9 10
    15 14 13 12 11
    

Each problem encourages practicing loops, conditionals, and alignment using spaces in Java.

Solution


public class patterns {
    public static void main (String[] args) {
        System.out.println ("\nProblem Statement: Write a Java program to print a square star pattern of size n.\n");
        squareStarPattern(5);
        System.out.println ("\nProblem Statement: Write a Java program to print a right triangle star pattern of height n.\n");
        rightTriangleStar (5);
        System.out.println ("\nProblem Statement: Write a Java program to print a Inverted right triangle star pattern of height n.\n");
        invertedRightTriangleStarPattern (5);
        System.out.println ("\nProblem Statement: Write a Java program to print a Pyramid Star Pattern star pattern of height n.\n");
        pyramidStarPattern (5);
        System.out.println ("\nProblem Statement: Write a Java program to print a Inverted Pyramid Star Pattern star pattern of height n.\n");
        InvertedPyramidStarPattern (5);
        System.out.println ("\nProblem Statement: Write a Java program to print a Diamond Star Pattern star pattern of height n.\n");
        diamondStarPattern (5);
        System.out.println ("\nProblem Statement: Write a Java program to print a hollow Pyramid pattern of height n.\n");
        hollowPyramid (5);
        System.out.println ("\nProblem Statement: Write a Java program to print a hollow diamond Pyramid pattern of height n.\n");
        hollowDiamondPyramid (5);
        System.out.println ("\nProblem Statement: Write a Java program to print a right triangle number pattern up to n rows.\n");
        rightTriangleNumberPattern (5);
        System.out.println ("\nProblem Statement: Write a Java program to print Pyramid Number Triangle of height n.\n");
        pyramidNumberPattern1 (5);
        System.out.println ("\nProblem Statement: Write a Java program to print Pascal's Triangle Triangle of height n.\n");
        PascalsTriangle (5);
        System.out.println ("\nProblem Statement: Write a Java program to print Floyd's Triangle of height n.\n");
        floydsTriangle (5);
        System.out.println ("\nProblem Statement: Write a Java program to print a square number pattern with numbers from 1 to n. Each row should start from the first number of the sequence.\n");
        squareNumberPattern (5);
        System.out.println ("\nProblem Statement: Write a Java program to print a hollow square pattern of size n, with a border of stars.\n");
        hollowSquarePattern (5);
        System.out.println ("\nProblem Statement: Write a Java program to print a zigzag number pattern of height n, with numbers increasing row by row.n");
        zigzagNumberPattern (5);
        System.out.println ("\nProblem Statement: Write a Java program to print k Triangle of height n.\n");
        kPattern (5);
        System.out.println ("\nProblem Statement: Write a Java program to print right Pascals Triangle of height n.\n");
        rightPascalsTriangle (5);
        System.out.println ("\nProblem Statement: Write a Java program to print right Butterfly Star Pattern of height n.\n");
        butterflyStarPattern (5);
        System.out.println ("\nProblem Statement: Write a Java program to print right Stop watch Star Pattern of height n.\n");
        stopWatchPattern (5);
        System.out.println ("\nProblem Statement: Write a Java program to print right Stop watch Hollow Star Pattern of height n.\n");
        stopWatchHollowPattern (5);

    }
    /*
  Problem Statement: Write a Java program to print a square star pattern of size n.

  Example (for ( n = 5 )):

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

   * */
    public static void squareStarPattern(int n){
        for (int i = 0; i < n; i++) {
            for (int j = 0; j <n; j++) {
                System.out.print("* ");
            }
            System.out.println ();
        }
    }
    /*
    Right Triangle Star Pattern

    Problem Statement: Write a Java program to print a right triangle star pattern of height n.

    Example (for ( n = 5 )):
     *
     **
     ***
     ****
     *****
 */
    public static void rightTriangleStar(int n){
        for (int i = 0; i < n; i++) {
            for (int j = 0; j <=i; j++) {
                System.out.print("* ");
            }
            System.out.println ();
        }
    }
    public static void invertedRightTriangleStarPattern(int n){
        for (int i = 0; i < n; i++) {
            for (int j = i; j < n; j++) {
                System.out.print("* ");
            }
            System.out.println ();
        }
    }
    /*
                 *
                ***
               *****
              *******
             *********

     */
    public static void pyramidStarPattern(int n){
        for (int i = 0; i < n; i++) {
            for (int j = i; j < n; j++) {
                System.out.print(" ");
            }
            for (int j = 0; j < (2*i)+1; j++) {
                System.out.print("*");
            }
            System.out.println ();
        }
    }
    public static void InvertedPyramidStarPattern(int n){
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < i; j++) {
                System.out.print(" ");
            }
            for (int j = 0; j < (2*(n-i))-1; j++) {
                System.out.print("*");
            }
            System.out.println ();
        }
    }
    /*
Problem Statement: Write a Java program to print a diamond star pattern of height n
             *
            ***
           *****
          *******
         *********
          *******
           *****
            ***
             *

* */
    public static void diamondStarPattern2(int n){
        for (int i = 0; i < n; i++) {
            for (int j = i; j < n; j++) {
                System.out.print(" ");
            }
            for (int j = 0; j < (2*i)+1; j++) {
                System.out.print("*");
            }
            System.out.println ();
        }
        for (int i = 0; i < n-1; i++) {
            for (int j = 0; j < i+2; j++) {
                System.out.print(" ");
            }
            for (int j = 0; j < (2*(n-i-1))-1; j++) {
                System.out.print("*");
            }
            System.out.println ();
        }
    }
    public static void diamondStarPattern3(int n){
        for (int i = 0; i < n; i++) {
            for (int j = i; j < n; j++) {
                System.out.print(" ");
            }
            for (int j = 0; j < (2*i)+1; j++) {
                System.out.print("*");
            }
            System.out.println ();
        }
        for (int i = n - 2 ; i >= 0; i++) {
            for (int j = 0; j < n - i -1; j++) {
                System.out.println (" ");
            }
            for (int j = 0; j < 2*i + 1; j--) {
                System.out.println ("*");
            }
        }
    }
    public static void diamondStarPattern(int n){
        for (int i = 0; i < n; i++) {
            System.out.print (" ".repeat (n-i-1));
            System.out.print ("*".repeat (2*i+1));
            System.out.println ();
        }
        for (int i = n - 2 ; i >= 0; i--) {
            System.out.print (" ".repeat (n-i-1));
            System.out.print ("*".repeat (2*i+1));
            System.out.println ();
        }
    }
    /*
Problem Statement: Write a Java program to print a hollow pyramid of height n.
         *
        * *
       *   *
      *     *
     *********

     */
    public static void hollowPyramid(int n){
        for (int i = 0; i < n; i++) {
            for (int j = n - i; j >= 0; j--) {
                System.out.print (" ");
            }
            for (int j = 0; j < 2*i+1; j++) {
                if((j == 0 || j == 2*i || i == n-1)){
                    System.out.print ("*");
                }else {
                    System.out.print (" ");
                }
            }
            System.out.println ();
        }
    }
    /*
Problem Statement: Write a Java program to print a hollow diamond star pattern of height n.

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


     */
    public static void hollowDiamondPyramid(int n){
        for (int i = 0; i < n; i++) {
            for (int j = n - i-2; j >= 0; j--) {
                System.out.print (" ");
            }
            for (int j = 0; j < 2*i+1; j++) {
                if((j == 0 || j == 2*i)){
                    System.out.print ("*");
                }else {
                    System.out.print (" ");
                }
            }
            System.out.println ();
        }
        for (int i = n-2; i >= 0; i--) {
            for (int j = 0; j < n-i-1; j++) {
                System.out.print (" ");
            }
            for (int j = 0; j < 2*i+1; j++) {
                if((j == 0 || j == 2*i)){
                    System.out.print ("*");
                }else {
                    System.out.print (" ");
                }
            }
            System.out.println ();
        }
    }
    /*
    Right Triangle Number Pattern
    Problem Statement: Write a Java program to print a right triangle number pattern up to n rows.
     1
     12
     123
     1234
     12345

    */
    public static void rightTriangleNumberPattern(int n){
        for (int i = 0; i < n; i++) {
            for (int j = 0; j <= i; j++) {
                System.out.print (j+1);
            }
            System.out.println ();
        }
    }
    /*

    Problem Statement: Write a Java program to print Pascal's Triangle of height n.
       1
      1 1
     1 2 1
    1 3 3 1
   1 4 6 4 1

    */
    public static void PascalsTriangle(int n){
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < n-i-1; j++) {
                System.out.print (" ");
            }
            for (int j = 0; j <=i; j++) {
                int p = factorial (i)/(factorial (j)*factorial ((i-j)));
                System.out.print (" "+p);
            }
            System.out.println ();
        }
    }
    private static int factorial(int n){
        if (n ==0){
            return 1;
        }
        int fact = 1;
        for (int i = 1; i <=n ; i++) {
            fact*=i;
        }
        return fact;
    }
    /*

    Problem Statement: Write a Java program to print Pascal's Triangle of height n.
        1
       1 2
      1 2 3
     1 2 3 4
    1 2 3 4 5
    */
    public static void pyramidNumberPattern(int n){
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < n-i-1; j++) {
                System.out.print (" ");
            }
            int count =1 ;
            for (int j = 0; j < 2*i+1; j++) {
                if(j%2 == 0){
                    System.out.print (count);
                    count++;
                }else {
                    System.out.print(" ");
                }
            }
            System.out.println ();
        }
    }
    public static void pyramidNumberPattern1(int n){
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < n-i-1; j++) {
                System.out.print (" ");
            }
            for (int j = 0; j <=i; j++) {
                int count = j+1;
                System.out.print (" " + count);
            }
            System.out.println ();
        }
    }
    /*
    Problem Statement: Write a Java program to print Floyd's Triangle of height n.
    1
    2 3
    4 5 6
    7 8 9 10
    11 12 13 14 15

    */
    public static void floydsTriangle(int n){
        int count = 1;
        for (int i = 0; i < n; i++) {
            for (int j = 0; j <= i; j++) {
                System.out.print (" "+count++);
            }
            System.out.println ();
        }
    }

    /*
    Problem Statement: Write a Java program to print a square number pattern with numbers from 1 to n. Each row should start from the first number of the sequence.
    1 2 3 4
    5 6 7 8
    9 10 11 12
    13 14 15 16

    */
    public static void squareNumberPattern(int n){
        int count = 1;
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < n; j++) {
                System.out.print (count++ + " ");
            }
            System.out.println ();
        }
    }

    /*
    Problem Statement: Write a Java program to print a hollow square pattern of size n, with a border of stars.

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

    */
    public static void hollowSquarePattern (int n) {
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < n; j++) {
                if (j == 0 || j == n-1 || i == 0 || i == n -1 ){
                    System.out.print ("* ");
                }else {
                    System.out.print ("  ");
                }
            }
            System.out.println ();
        }
    }
    /*
    Problem Statement: Write a Java program to print a zigzag number pattern of height n, with numbers increasing row by row.
    1
    2 3
    6 5 4
    7 8 9 10
    15 14 13 12 11

    */
    public static void zigzagNumberPattern (int n) {
        int count = 1;
        for (int i = 0; i < n; i++) {
            for (int j = 0; j <= i; j++) {
                if (i != 0 && i%2 == 0){
                    System.out.print (count + " ");
                    count--;
                }else {
                    System.out.print (count + " ");
                    count++;
                }
            }
            if (i % 2 != 0){
                count = count + i+1;
            }else if(i!=0){
                count += i+2;
            }
            System.out.println ();
        }
    }
    /*
    K Pattern

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

     */
    public static void kPattern(int n){
        for (int i = n; i > 0; i--) {
            for (int j = 0; j <i; j++) {
                System.out.print ("* ");
            }
            System.out.println ();
        }
        for (int i = 1; i < n; i++) {
            for (int j = 0; j <=i; j++) {
                System.out.print ("* ");
            }
            System.out.println ();
        }
    }
    /*

    Problem Statement: Write a Java program to print right Pascals Triangle of height n.
    *
    * *
    * * *
    * * * *
    * * * * *
    * * * *
    * * *
    * *
    *

    */
    public static void rightPascalsTriangle(int n){
        for (int i = 0; i < 2*n; i++) {
            for (int j = 0; i < n && j <=i; j++) {
                System.out.print ("* ");
            }
            for (int j = n-1; i >= n && j > i - n; j--) {
                System.out.print ("* ");
            }
            System.out.println ();
        }
    }
    /*
    Problem Statement: Write a Java program to print right Butterfly Star Pattern of height n.

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

    */
    public static void butterflyStarPattern (int n)     {
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < 2*n; j++) {
                if(j <= i || j >= 2*n-i-1){
                    System.out.print ("* ");
                }else {
                    System.out.print ("  ");
                }
            }

            System.out.println ();
        }
        for (int i = n - 1; i >= 0; i--) {
            for (int j = 0; j < 2*n; j++) {
                if(j <= i || j >= 2*n-i-1){
                    System.out.print ("* ");
                }else {
                    System.out.print ("  ");
                }
            }

            System.out.println ();
        }
    }
    /*
    Problem Statement: Write a Java program to print right Stop watch Star Pattern of height n.

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

    */
    public static void stopWatchPattern(int n){
        for (int i = n -1 ; i >= 0; i--) {
            for (int j = 0; j < n-(i)-1; j++) {
                System.out.print ("  ");
            }
            for (int j = 0; j <= 2*i; j++) {
                System.out.print("* ");
            }
            System.out.println ();
        }
        for (int i = 1 ; i <= n-1; i++) {
            for (int j = 0; j < n-(i)-1; j++) {
                System.out.print ("  ");
            }
            for (int j = 0; j <= 2*i; j++) {
                System.out.print("* ");
            }
            System.out.println ();
        }
    }
    /*
    Problem Statement: Write a Java program to print right Stop watch Hollow Star Pattern of height n.

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

    */
    public static void stopWatchHollowPattern(int n){
        for (int i = n -1 ; i >= 0; i--) {
            for (int j = 0; j < n-(i)-1; j++) {
                System.out.print ("  ");
            }
            for (int j = 0; j <= 2*i; j++) {
                if(j == 0 || j == 2*i || i == 0 || i == n-1){
                    System.out.print("* ");
                }else {
                    System.out.print("  ");
                }
            }
            System.out.println ();
        }
        for (int i = 1 ; i <= n-1; i++) {
            for (int j = 0; j < n-(i)-1; j++) {
                System.out.print ("  ");
            }
            for (int j = 0; j <= 2*i; j++) {
                if(j == 0 || j == 2*i || i == 0 || i == n-1){
                    System.out.print("* ");
                }else {
                    System.out.print("  ");
                }
            }
            System.out.println ();
        }
    }
}