# Java program to display pascal triangle

Let’s learn java program to display pascal triangle.

## Java program to display pascal triangle

Pascal triangle is a triangle of binomial coefficients arranged in the form of a triangle. It is named after french mathematician Blaise Pascal. Pascal triangle looks like this,

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

In the above triangle there are five rows. First row starts with digit 1. Then each digit in a row is the sum of left digit and right digit of above row. Suppose, if a digit is missing in the above row, it is assumed as 0.

NOTE:

• diagonals adjacent to the border diagonals contain natural numbers in an order.
• sum of numbers in each row is twice the sum of numbers in above row.

Binomial coefficient can be calculated using formula,

C(n,r) = n!/((n-r)!*r!)

Time complexity: O(n²) where n is number of lines.

Here’s the java program to print pascal triangle,

```import java.util.Scanner;

public class PascalsTriangleJava
{
public static void main(String[] args)
{
System.out.println("Please enter number of rows : ");
Scanner sc = new Scanner(System.in);
int num = sc.nextInt();
int row = num;
int number = 1;

for(int i = 0; i < num; i++)
{
for(int r = 1; r <= row; r++)
{
System.out.print(" ");
}
number = 1;
for(int j = 0; j <= i; j++)
{
System.out.print(number + " ");
number = number * (i - j) / (j + 1);
}
row--;
System.out.println();
sc.close();
}
}
}

```

Output:

Also read – garbage collection in java