Question

Given a string S that contains lowercase English letters representing different types of

candies. A substring of a string S is a string Ssub that occurs in S. For example, "twix" is a

candy name which is the substring of "twtwixtwixnerdstwixnerds". Each candy costs 1 unit.

You can pick some consecutive candies such that you can create a palindrome of length L by

using some or all picked candies while the number of all possible cases K (all possible

palindromes) is given. The main goal is to find the minimum cost to create a palindrome of

length L. For example,

S= twtwixtwixnerdstwixnerds

L=8

K=4

P= twixtwix

Your task is to identify and define all possible inputs and outputs of a such given problem.

Use Java language.

Answer 1

import java.util.Scanner;
import java.util.HashSet;
import java.util.Set;
// Program to find the palindrome name of the candies in a String
//string: twtwixtwixnerdstwixnerds

public class Palindrome {

    // Function will return palindrome
    // sub-string to be added
   private static void searchPalindromeCandies(String str,int L) {
        String s1 = "",s2="";
        int N = str.length(), count = 0;
      
       // to hold the pallindrome strings
        Set<String> palindromeArray = new HashSet<String>();
      
        System.out.println("Given string : " + str);
        System.out.println("\n******** Substring palindrome *******");
      
       //calculate the mid of the substring
       int mid=(L+1)/2;
       int minCost=0;
       boolean isFirstPallindromGot=false;
  
            for (int j = 0; j <= N-mid; j++) {
              
                s1 = str.substring(j, j+mid);
               s2=s1+s1;
              
               //count the min cost to find the first palindrome
               if(!isFirstPallindromGot)
                   minCost++;
              
                if (str.contains(s2)) {
                    palindromeArray.add(s2);
                   isFirstPallindromGot=true;
                  
                }
            }

       //print all palindrome strings
        System.out.println(palindromeArray);
      
        for (String s : palindromeArray)
            System.out.println(s + " - sub-string is a palindrome.");
        System.out.println("The no.of palindrome are: "+ palindromeArray.size());
       System.out.println("The Min. Cost : "+minCost);
      
    }
  
    // Driver program
    public static void main(String[] args)
    {
      
       Scanner sc=new Scanner(System.in);
      
       //user string input
       System.out.print("Enter Any String: ");
       String str = sc.next();
      
       //Length of Palindrome (two times of candies name)
       System.out.print("Enter Length Of Pallindrome: ");
       int L=sc.nextInt();
       searchPalindromeCandies(str,L);
    }
}