Simple java pyramid – using system out. Printf() format output

Objectives:

I am trying to generate a pyramid similar to the format given below This requires a basic Java program that accepts user input, converts numbers to strings, uses nested loops, and generates formatted output The following is an example of the required output using 8 lines

Enter the number of lines: 8

               1              
             2 1 2            
           3 2 1 2 3          
         4 3 2 1 2 3 4        
       5 4 3 2 1 2 3 4 5      
     6 5 4 3 2 1 2 3 4 5 6
   7 6 5 4 3 2 1 2 3 4 5 6 7
 8 7 6 5 4 3 2 1 2 3 4 5 6 7 8

Question:

I believe I have the logic to add numbers correctly, but I need help formatting the pyramid I can add spaces between each number, but if the number of lines is > 10, then you can see that the format is screwed up On the last line (line 10), the number 1 is no longer centered What is the reason and how can I solve this problem?

I know I can use system out. Printf ("% 4S", value), but you want to find a way to do this if the number of rows is > 1000 Thank you in advance for providing me with any guidance from more knowledgeable people

1
                 2 1 2
               3 2 1 2 3
             4 3 2 1 2 3 4
           5 4 3 2 1 2 3 4 5
         6 5 4 3 2 1 2 3 4 5 6
       7 6 5 4 3 2 1 2 3 4 5 6 7
     8 7 6 5 4 3 2 1 2 3 4 5 6 7 8
   9 8 7 6 5 4 3 2 1 2 3 4 5 6 7 8 9
 10 9 8 7 6 5 4 3 2 1 2 3 4 5 6 7 8 9 10

My current code:

import java.util.Scanner;

public class Pyramid1
{
    public static void main(String[] args)
    {
        int i,j,k,a;

        //Create a Scanner object
        Scanner input = new Scanner (system.in);

        //Prompt the user to enter number of rows in pyramid
        System.out.print("Enter number of rows: ");

        int rows = input.nextInt();
        a = rows;

        //Logic
        for (i=1; i<=rows; i++)
        {
            for (j=a; j>1; j--)
            {
                System.out.printf(" %s"," ");
            }

            for (k=i; k!=0; k--)
            {
                String str1 = "" + k;
                System.out.printf(" %s",str1);
            }
            a--;

            for (int l=2; l<=i; L++)
            {
                String str2 = "" + l;
                System.out.printf(" %s",str2);
            }

            System.out.println();
        }
    }
}

Solution

Here is the code for your request

import java.util.Scanner;

public class Pyramid1
{   
    public static void main(String[] args)
    {
        int i,a;

        //Create a Scanner object
        Scanner input = new Scanner (system.in);

        //Prompt the user to enter number of rows in pyramid
        System.out.print("Enter number of rows: ");

        int rows = input.nextInt();
        a = rows;

        int length = ("" + rows).length();

        String str = " %"+length+"s";

        for (i=1; i<=rows; i++)
        {
            for (j=a; j>1; j--)
            {
                System.out.printf(str," ");
            }

            for (k=i; k!=0; k--)
            {
                String str1 = "" + k;
                System.out.printf(str,str1);
            }
            a--;

            for (int l=2; l<=i; L++)
            {
                String str2 = "" + l;
                System.out.printf(str,str2);
            }

            System.out.println();
        }
    }
}