Question

2. Write a Java program that reads a series of input lines from given file “name.txt”, and sorts them into alphabetical order, ignoring the case of words. The program should use the merge sort algorithm so that it efficiently sorts a large file.

Contents of names.text

Slater, KendallLavery, RyanChandler, Arabella "Babe"Chandler, StuartKane, EricaChandler, Adam JrSlater, ZachMontgomery, JacksonChandler, KrystalMartin, JamesMontgomery, BiancaCortlandt, PalmerDevane, AidanMadden, JoshHayward, DavidLavery,k JonathanSmythe, GreenleeCortlandt, OpalMcDermott, AnnieHenry, DiGrey, MariaEnglish, BrookeKeefer, JuliaMartin, JosephMontgomery, LilyDillon, AmandaColby, LizaStone, Mary FrancesChandler, ColbyFrye, DerekMontgomery, ReggieMontgomery, SeanSantos, HayleySantos, MateoDillon, JanetJefferson, KelseyChandler, MarianFargate, MyrtleHenry, DelCodahy, LiviaWarner, AnitaLavery, SpikeMartin, RuthMontgomery, Barbara

Answer 1

ANSWER:

I have provided the properly commented and indented code so you can easily copy the code as well as check for correct indentation.
I have provided the output image of the code so you can easily cross-check for the correct output of the code.
Have a nice and healthy day!!

CODE

import java.util.*;
import java.io.*;

public class Main
{

  public static String [] mergeSort(String [] array){
        String [] list = array;
        
        if(list.length > 1)
        {
            // mid of list
            int mid = list.length / 2;
 
            // Split left part
            String[] left = new String[mid];
            for(int i = 0; i < mid; i++)
            {
                left[i] = list[i];
            }
             
            // Split right part
            String[] right = new String[list.length - mid];
            for(int i = mid; i < list.length; i++)
            {
                right[i - mid] = list[i];
            }
            // calling mergeSort
            mergeSort(left);
            mergeSort(right);
 
            int i = 0;
            int j = 0;
            int k = 0;
 
            // Merge left and right arrays
            while(i < left.length && j < right.length)
            {
                // compare left right string
                // using
                if(left[i].compareTo(right[j]) < 0)
                {
                    list[k] = left[i];
                    i++;
                }
                else
                {
                    list[k] = right[j];
                    j++;
                }
                k++;
            }
            // Collect remaining elements
            while(i < left.length)
            {
                list[k] = left[i];
                i++;
                k++;
            }
            while(j < right.length)
            {
                list[k] = right[j];
                j++;
                k++;
            }
        }
        

        return list;
    }


        public static void main(String[] args) {
            // reading names.txt
                File namesFile = new File("names.txt");
    try
    {
      // creating scanning object on file object
                  Scanner reader = new Scanner(namesFile);
                  // reading file line by line,
                  // creating complete file string object 
                  String data = "";
                  while (reader.hasNextLine()) {
                    // reading line
                    String line = reader.nextLine();
                    // storing line in data, using , seprator
                    data = ","+line;
                  }
                  // display content 
                  // System.out.println(data);
                
                  // spliting string on , using string split method 
                  String[] names = data.split(",");
      // using strip to remove trailing spaces from names
      for(int i=0;i<names.length;i++){
        names[i] = names[i].trim();
        System.out.println(names[i]);
      }
                
                  // merges rot
      String[] sorted = mergeSort(names);
                  System.out.println("");
      // using strip to remove trailing spaces from names
      for(int i=0;i<sorted.length;i++){
        System.out.println(sorted[i]);
      }      
    }
    catch (FileNotFoundException ex)  
    {
        // insert code to run when exception occurs
        System.out.println("FIle not found");
    }
                
            
        }
}

OUTPUT IMAGE

SORTED