Pascal Triangle in Java

Here you will learn about pascal triangle in java with a program example.

What is Pascal’s Triangle?

It is a triangular array of the binomial coefficients. It is a number pattern which starts with 1 at top and then placing numbers below it in triangular pattern.

Each number is obtained by adding two numbers above it. Take below example, here 4 is obtained by adding 1 and 3 above it.

Below I have shared the java program to print pascal triangle. Each term in the pattern is obtained by using combination formula given below.

Program for Pascal Triangle in Java

package com;

import java.util.Scanner;

public class PascalTriangleJava {
	public static void main(String args[]) {
		int i,j,k,n;
		Scanner sc = new Scanner(System.in);
	
		System.out.println("How many lines?");
		n = sc.nextInt();
		
		for(i = 0; i < n; ++i) {
			//this loop will print spaces at starting of each row
			for(j = 1; j <= (n-i-1); ++j) {
				System.out.print(" ");
			}
			
			//this loop will calculate each value in a row and print it
			for(k = 0; k <= i; ++k) {
				System.out.print(fact(i)/(fact(i-k)*fact(k)) + " ");
			}
			
			System.out.print("\n");    //print new line after each row
		}
	}

	//calculate factorial
	static long fact(int x) {
		int i;
		long f = 1;
		
		for(i = 1; i <= x; ++i) {
			f = f*i;
		}
		
		return f;
	}
}

Output

Comment below if you have any doubts related to above program.