Question

Decode the logic and print the Pattern that corresponds to given input. If N= 3 then pattern will be : 10203010011012 **4050809 ****607 If N= 4 then pattern will be: 1020304017018019020 **50607014015016 ****809012013 ******10011

Answer 1

Explanation of the pattern:
For example, if N=4, there will be 4 sections in the output separated by a space and asteriks.
The first section contains 2*4 numbers, ie., 1 to 4 and 17 to 20, separated by zeroes (1020304017018019020), the second section contains 2*(N-1),ie., 2*3 numbers (5 to 7 and 14 to 16) separated by zeroes (50607014015016), the third sections contains 2*2 numbers (8 to 9 and 12 to 13) separated by zeroes, ie., (809012013), the last section contains 2*1 numbers (10, 11) separated by zero ie., (10011)

Every two sections are separated by a space followed by 2*i asteriks where i starts from 1 and increases by 1 for every gap between two sections

A representation of numbers present in each section in this example

1,2,3,4   17,18,19,20 (Section 1)
5,6,7 14,15,16   (Section 2)
8,9 12,13 (Section 3)
10 11 (Section 4)

Here is the code written in Java.

package com.HomeworkLib.decodepattern;

import java.util.Scanner;

public class DecodePattern {

   public static void main(String[] args) {

       try(Scanner scanner = new Scanner(System.in)){
           System.out.println("Please enter the input value, N: ");
           int N = scanner.nextInt();
           StringBuffer buffer = new StringBuffer();
//To get the maximum value in the pattern
           int maxCount = getMaxCount(N);
           int increasingValue = 1;
           int decreasingValue=maxCount;
           int starCount=1;
          
           for (int i=N; i>=1; i--) {
              
               buffer.append(getSection(increasingValue, i));
               buffer.append("0");
               buffer.append(getSection(decreasingValue-i+1,i));
              
               if (i!=1) {
                   buffer.append(" ");
                   buffer.append(getStars(2*starCount));
               }
              
               starCount++;
               decreasingValue-=i;
               increasingValue+=i;
              
           }
          
           System.out.println("Output: " + buffer.toString());
       }
   }

   private static int getMaxCount(int N) {
       int maxCount = 0;
       for (int i=1; i<=N; i++) {
           maxCount+=i;
       }
      
       maxCount = 2*maxCount;
       return maxCount;
   }
  
   private static String getStars(int n) {
       String nStars="";
       for (int i=1; i<=n; i++) {
           nStars+= "*";
       }
       return nStars;
   }
  
   private static StringBuffer getSection(int start, int length) {
       StringBuffer buffer = new StringBuffer();
       buffer.append(Integer.toString(start));
       for (int i=1; i<length; i++) {
           buffer.append("0");
           buffer.append(Integer.toString(start+i));
       }
       return buffer;
   }

}