Java Program to Print Pyramid Number Pattern

Here we are getting a step ahead in printing patterns as in generic we usually play with columnar printing in the specific row keep around where elements in a row are either added up throughout or getting reduced but as we move forward we do start playing with rows which hold for outer loop in our program.

Illustrations:

A pyramid number pattern of row size r = 5 would look like: 1 2 3 2 3 4 5 4 3 4 5 6 7 6 5 4 5 6 7 8 9 8 7 6 5

A pyramid number pattern of row size r = 4 would look like: 1 2 3 2 3 4 5 4 3 4 5 6 7 6 5 4 

Approach:

1. For loop will be used to print each row in the pyramid.
2. Inside the for loop we will use two loops :
3. One loop is used to print the spaces
4. The second loop will be used to print the numbers.

Implementation:

// Java Program to Print the Pyramid pattern // Main class public class GFG {  // Main driver method  public static void main(String[] args)  {  int num = 5;  int x = 0;  // Outer loop for rows  for (int i = 1; i <= num; i++) {  x = i - 1;  // inner loop for "i"th row printing  for (int j = i; j <= num - 1; j++) {  // First Number Space  System.out.print(" ");  // Space between Numbers  System.out.print(" ");  }  // Pyramid printing  for (int j = 0; j <= x; j++)  System.out.print((i + j) < 10  ? (i + j) + " "  : (i + j) + " ");  for (int j = 1; j <= x; j++)  System.out.print((i + x - j) < 10  ? (i + x - j) + " "  : (i + x - j) + " ");  // By now we reach end for one row, so  // new line to switch to next  System.out.println();  }  } } 

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

Time complexity: O(N^2) where N is given row size.
Auxiliary space: O(1), using constant extra space.