NumberPatterns.java

public class NumberPatterns {
    /**
     * Pattern: Increasing Number Triangle
     * 1
     * 2 3
     * 4 5 6
     * 7 8 9 10
     * 11 12 13 14 15
     * Time Complexity: O(n²)
     * Space Complexity: O(1)
     */
    static void Increasing_Number_Triangle_Pattern(int n) {
        int start = 1;
        for (int i = 0; i < n; i++) {
            for (int j = 0; j <= i; j++) {
                System.out.print(start + " ");
                start++;
            }
            System.out.println();
        }
    }

    /**
     * Pattern: Binary Number Triangle
     * 1
     * 0 1
     * 1 0 1
     * 0 1 0 1
     * 1 0 1 0 1
     * Time Complexity: O(n²)
     * Space Complexity: O(1)
     */

    static void Binary_Number_Triangle_Pattern(int n) {
        int start;
        for (int i = 0; i < n; i++) {
            if (i % 2 == 0)
                start = 1;
            else
                start = 0;

            for (int j = 0; j <= i; j++) {
                System.out.print(start);
                start = 1 - start;
            }
            System.out.println();
        }
    }

    /**
     * Pattern: Number Crown Pattern
     * 1--------1
     * 12------21
     * 123----321
     * 1234--4321
     * 1234554321
     * Time Complexity: O(n²)
     * Space Complexity: O(1)
     */

    static void Number_Crown_Pattern(int n) {
        for (int i = 1; i <= n; i++) {
            for (int j = 1; j < i + 1; j++) {
                System.out.print(j);
            }
            for (int j = 2 * n; j > i * 2; j--) {
                System.out.print("-");
            }
            for (int j = i; j >= 1; j--) {
                System.out.print(j);
            }
            System.out.println();

        }
    }

    public static void main(String[] args) {
        System.out.println("=== Pattern 1: Increasing Number Triangle Pattern ===");
        Increasing_Number_Triangle_Pattern(5);

        System.out.println("\n=== Pattern 2: Binary Number Triangle Pattern ===");
        Binary_Number_Triangle_Pattern(5);

        System.out.println("\n=== Pattern 3: Number Crown Pattern ===");
        Number_Crown_Pattern(5);
    }
}