Java: Display Pascal's triangle

Last update on May 14 2025 13:00:30 (UTC/GMT +8 hours)

Pascal's Triangle

Write a Java program to display Pascal's triangle.

Construction of Pascal's Triangle:

As shown in Pascal's triangle, each element is equal to the sum of the two numbers immediately above it.

Test Data
Input number of rows: 5

Sample Solution:

Java Code:

import java.util.Scanner;
public class Exercise22 {

  public static void main(String[] args)
{
    int no_row,c=1,blk,i,j;
    System.out.print("Input number of rows: ");
    Scanner in = new Scanner(System.in);
		    no_row = in.nextInt();
    for(i=0;i<no_row;i++)
    {
        for(blk=1;blk<=no_row-i;blk++)
        System.out.print(" ");
        for(j=0;j<=i;j++)
        {
            if (j==0||i==0)
                c=1;
            else
               c=c*(i-j+1)/j;
            System.out.print(" "+c);
        }
        System.out.print("\n");
    }
}
}

Sample Output:

Input number of rows: 5                                                                                       
      1                                                                                                       
     1 1                                                                                                      
    1 2 1                                                                                                     
   1 3 3 1                                                                                                    
  1 4 6 4 1

Flowchart:

For more Practice: Solve these Related Problems:

• Write a Java program to display Pascal’s Triangle using a two-dimensional array.
• Write a Java program to generate Pascal’s Triangle recursively without using iterative loops.
• Write a Java program to compute the sum of each row in Pascal’s Triangle and display the results.
• Write a Java program to format Pascal’s Triangle so that each row is centered when printed.

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