Question

JAVA

* create Q3 class to implement comparator for a TreeSet. The purpose of
       * the comparator is to compare the alphabetic order of integers. With Q3,
       * the order of Integer elements will be sort according to the order of
       * digit Unicode.
       * For example, the value of {11,3,31,2} will return {11,2,3,31}
       * NOTE: You don't need to compare each digit one by one. Just compare them

System.out.println("Q3 = [15 marks] =================================");
       Set set = new TreeSet<>(new Q3());
       Integer[] arr3 = {11,3,31,2};
       set.addAll(Arrays.asList(arr3));
       for (Integer element: set)
           System.out.print(element+"\t");
       System.out.println();

implement stats method in Q4 class to perform statistics for the
       * occurrence of each character in the provided sentence string.
       * Save the results into a hashmap, with key = character and value = occurrence
       * For example, "no news is good news" should return a hashmap with value of
       * { =4, s=3, d=1, e=2, w=2, g=1, i=1, n=3, o=3}
       * NOTE: the first key indicates space.

String sentence = "no news is good news";
       System.out.println("Q5 = [15 marks] =================================");
       System.out.println(Q5.stats(sentence));

Answer 1

import java.util.Comparator;

import java.util.TreeSet;

   class The_Comparator implements Comparator<String> {

    public int compare(String str1, String str2)

    { String first_Str;

        String second_Str;

        first_Str = str1;

        second_Str = str2;

        return second_Str.compareTo(first_Str);

    }

}

  public class Tree_Set_Demo {

    public static void main(String[] args)

    {

        TreeSet<String> tree_set = new TreeSet<String>(new

        The_Comparator()); tree_set.add("G");

        tree_set.add("E");

        tree_set.add("E");

        tree_set.add("K");

        tree_set.add("S");

        tree_set.add("4");

        System.out.println("Set before using the comparator: "+

        tree_set);

   System.out.println("The elements sorted in descending"+

        "order:");

        for (String element : tree_set)

            System.out.print(element + " ");

    }

}

output:

Set before using the comparator: [S, K, G, E, 4]
The elements sorted in descendingorder:
S K G E 4

=================================
import java.io.*;
import java.util.*;
class OccurenceOfCharInString {
   static void characterCount(String inputString)
   {
       // Creating a HashMap containing char
       // as a key and occurrences as a value
       HashMap<Character, Integer> charCountMap
           = new HashMap<Character, Integer>();

       // Converting given string to char array

       char[] strArray = inputString.toCharArray();

       // checking each char of strArray
       for (char c : strArray) {
           if (charCountMap.containsKey(c)) {

               // If char is present in charCountMap,
               // incrementing it's count by 1
               charCountMap.put(c, charCountMap.get(c) + 1);
           }
           else {

               // If char is not present in charCountMap,
               // putting this char to charCountMap with 1 as it's value
               charCountMap.put(c, 1);
           }
       }

       // Printing the charCountMap
       for (Map.Entry entry : charCountMap.entrySet()) {
           System.out.println(entry.getKey() + " " + entry.getValue());
       }
   }

   // Driver Code
   public static void main(String[] args)
   {
       String str = "Abhi";
       characterCount(str);
   }
}
output:

A 1
b 1
h 1
i 1