Java Program to Print Star Pascal’s Triangle

// Java Program to Print Pascal's Triangle

// Importing input output classes
import java.io.*;

// Main Class
public class GFG {

	// Method 1
	// To find factorial of a number
	public int factorial(int a)
	{
		// Edge case
		// Factorial of 0 is unity
		if (a == 0)

			// Hence return 1
			return 1;

		// else recursively call the function over the
		// number whose facoial is to be computed
		return a * factorial(a - 1);
	}

	// Method 2
	// Main driver method
	public static void main(String[] args)
	{
		// Declare and initialize number whose
		// factorial is to be computed
		int k = 4;

		int a, b;

		// Creating an object of GFG class
		// in the main() method
		GFG g = new GFG();

		// iterating using nested for loop to traverse over
		// matrix

		// Outer for loop
		for (a = 0; a <= k; a++) {

			// Inner loop 1
			for (b = 0; b <= k - a; b++) {

				// Print white space for left spacing
				System.out.print(" ");
			}

			// Inner loop 2
			for (b = 0; b <= a; b++) {

				// nCr formula
				System.out.print(
					" "
					+ g.factorial(a)
						/ (g.factorial(a - b)
							* g.factorial(b)));
			}

			// By now, we are done with one row so
			// a new line
			System.out.println();
		}
	}
}