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:
- For loop will be used to print each row in the pyramid.
- Inside the for loop we will use two loops :
- One loop is used to print the spaces
- The second loop will be used to print the numbers.
Implementation:
Java
// Java Program to Print the Pyramid patternÂ
// Main classpublic class GFG {Â
    // Main driver method    public static void main(String[] args)    {        int num = 5;        int x = 0;Â
        // Outer loop for rows        for (int i = 1; i <= num; i++) {            x = i - 1;Â
            // inner loop for "i"th row printing            for (int j = i; j <= num - 1; j++) {Â
                // First Number Space                System.out.print(" ");Â
                // Space between Numbers                System.out.print(" ");            }Â
            // Pyramid printing            for (int j = 0; j <= x; j++)                System.out.print((i + j) < 10                                     ? (i + j) + " "                                     : (i + j) + " ");Â
            for (int j = 1; j <= x; j++)                System.out.print((i + x - j) < 10                                     ? (i + x - j) + " "                                     : (i + x - j) + " ");Â
            // By now we reach end for one row, so            // new line to switch to next            System.out.println();        }    }} |
Output
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.
