Number Pattern Spiral in Java: Explanation & Practice

Problem summary

Print numbers 1 to n² in a triangular increasing pattern.

Starter code

public class Main {
    public static void main(String[] args) {
        int n = 4; // Test case 1
        
        // Print pattern:
        // 1
        // 2 3
        // 4 5 6
        // 7 8 9 10
    }
}

Expected output and test cases

• 4-row number triangle

  1
  2 3
  4 5 6
  7 8 9 10

• 3-row number triangle

  1
  2 3
  4 5 6

Hints

1. Keep a counter starting at 1
2. Row i has i numbers
3. Increment counter after each print

Related Control Flow exercises

• Practice Advanced Leap Year in Java
• Practice Number Classification in Java

Practice all Control Flow exercises · Run this idea in the Java compiler