ICTAK04 - Editorial

Problem Link:

https://www.codechef.com/ICTAK17/problems/ICTAK04

Difficulty: Easy-Medium

Prerequisites: Loops

Problem: Create a reverse pyramid of numbers for a given integer number. Explanation:

In Reverse pyramid number pattern of N rows, i th row contains (i-1) space characters followed by (2*i - 1) characters. First take the number of rows in the pattern as input from user and store it in an integer variable "rowCount". One iteration of outer for loop will print a row of inverted pyramid. For any row i, inner for loop • Step:1 first prints i-1 spaces followed by a for loop which prints “rowCount” number of character.( i.e. numbers from 1 to rowCount) For an example if rowCount=5, after completing this step of inner loop the output will be “1 2 3 4 5” • Step:2 then the next for loop will print “rowCount-1” number of characters( i.e. numbers from rowCount-1 to 1) For an example if rowCount=5, after completing first step of inner loop the output will be “1 2 3 4 5” and at the end this step of inner loop, output will be “1 2 3 4 5 4 3 2 1”

Eg : rowCount= 5 • After first outer loop iteration: 1 2 3 4 5 4 3 2 1 • After second outer loop iteration: 1 2 3 4 5 4 3 2 1 1 2 3 4 3 2 1 • After third outer loop iteration: 1 2 3 4 5 4 3 2 1 1 2 3 4 3 2 1 1 2 3 2 1 • After fourth outer loop iteration: 1 2 3 4 5 4 3 2 1 1 2 3 4 3 2 1 1 2 3 2 1 1 2 1 • After fifth outer loop iteration: 1 2 3 4 5 4 3 2 1 1 2 3 4 3 2 1 1 2 3 2 1 1 2 1 1 Solution:

import java.util.; import java.lang.; import java.io.*; class MainClass { public static void main(String[] args) { Scanner sc = new Scanner(System.in); int noOfRows = sc.nextInt(); int rowCount = noOfRows;

   for (int i = 0; i < noOfRows; i++)
    {
                   for (int j = 1; j <= i*2; j++)
        {
            System.out.print(" ");
        }
         for (int j = 1; j <= rowCount; j++)
        {
            System.out.print(j+" ");
        }
         for (int j = rowCount-1; j >= 1; j--)
        {
            System.out.print(j+" ");
        }
        System.out.println();
         rowCount--;
    }
}

}