Has anyone solved this?

Question about the task

Resolved

I get the same results as they do with their examples, at least I think i do, the requirements are a convoluted mess. Anyone have any suggestions?

Read 2 file names from the console: file1 and file2.
Both files contain text, but file2 is an updated version of file1. Some of the lines are still the same.
You need to create a merged version of the lines by writing them to the lines list.
The ADDED and REMOVED labels can't be used consecutively—they must always separated by the SAME label.
The example includes empty lines for clarity.
Neither the original file nor the updated file have empty lines!

Example 1:
original updated merged file1: file2: Result: (lines) line1 line1 SAME line1 line2 REMOVED line2 line3 line3 SAME line3 line4 REMOVED line4 line5 line5 SAME line5 line0 ADDED line0 line1 line1 SAME line1 line2 REMOVED line2 line3 line3 SAME line3 line4 ADDED line4 line5 line5 SAME line5 line0 REMOVED line0

Example 2:
original updated merged file1: file2: Result: (lines) line1 line1 SAME line1 line0 ADDED line0

In the example, empty lines mean that the line is not in the specified file.

Requirements:

The Solution class must contain a LineItem class.
The Solution class must have an enum called Type.
The Solution class must have a public static List<LineItem> field called lines that is initialized immediately.
In the main(String[] args) method, the program must read file names from the console (use BufferedReader).
In the main(String[] args) method, the BufferedReader used for reading input from the console must be closed after use.
The program must read the contents of the first and second file (use FileReader).
The file input streams (FileReader) must be closed.
The lines list should contain the merged version of the lines from the files. Each line should start with the label ADDED, REMOVED, or SAME, depending on the action taken.

package com.codegym.task.task19.task1916; import java.io.*; import java.lang.invoke.SwitchPoint; import java.util.ArrayList; import java.util.LinkedHashMap; import java.util.List; import java.util.Map; /* Tracking changes */ public class Solution { static boolean debug = false; // debug mode true = on; false = off //where ever you see debug in my code won't be run when this is set to false. public static List<LineItem> lines = new ArrayList<>(); public static void main(String[] args) throws IOException { String[] fileNames = new String[2]; if(debug){ fileNames[0] = "C:\\Users\\COMPUTER\\Desktop\\temp\\one.txt"; fileNames[1] = "C:\\Users\\COMPUTER\\Desktop\\temp\\two.txt"; }else { BufferedReader userInput = new BufferedReader(new InputStreamReader(System.in)); fileNames[0] = userInput.readLine(); fileNames[1] = userInput.readLine(); userInput.close(); } //declare array lists to hold each files contents ArrayList<String> fileOneContents = getContents(fileNames[0]), fileTwoContents = getContents(fileNames[1]); //if(debug) System.out.println(fileOneContents + "\n" + fileTwoContents); //creates LinkedHashMap and delegates sorting to method LinkedHashMap<String,Type> orderedResults = sortFileContents(fileOneContents, fileTwoContents); if (debug) for(Map.Entry<String, Type> pair : orderedResults.entrySet()) System.out.println(pair.getValue() + " : " + pair.getKey()); //adds each item from linkedhashmap to static list: lines for(Map.Entry<String,Type> pair : orderedResults.entrySet()){ lines.add(new LineItem(pair.getValue(), pair.getKey())); } if(debug) { for (int i = 0; i < lines.size(); i++) { System.out.println(lines.get(i).type + " " + lines.get(i).line); } } } // orders the file content's passed to it and tags each line as same, added, removed; adds them to linkedhashmap which is returned private static LinkedHashMap<String, Type> sortFileContents(ArrayList<String> fileOneContents, ArrayList<String> fileTwoContents) { LinkedHashMap<String, Type> returnValues = new LinkedHashMap<>(); ArrayList<String> order; // initializes first values of the order: adds SAME and REMOVED order = getStartingOrder(fileOneContents, fileTwoContents); // enter all lines to be added in correct order addInsterts(order, fileOneContents, fileTwoContents); // enters everything into the linked hash map for(String x : order){ Type type = null; String[] values = x.split("亦"); switch (values[0]){ case "ADDED": type = Type.ADDED; break; case "REMOVED": type = Type.REMOVED; break; case "SAME": type = Type.SAME; break; default: break; } returnValues.put(values[1],type); } return returnValues; } // adds in all new lines of code at the index 1 after the last SAME, accounts for REMOVE private static void addInsterts(ArrayList<String> order, ArrayList<String> StartingFile, ArrayList<String> updatedFile) { int index = 0; //iterates through each line of the updated file for(int i = 0; i < updatedFile.size();i++){ // step one, check if the line is contained, increases index number if true if(StartingFile.contains(updatedFile.get(i))) index++; else{ // step 2 if 1 is false: adds line at element index, increases index, or if index is past size, puts it at the end if(index != order.size()){ order.add(index, "ADDED"+"亦"+updatedFile.get(i)); index++; }else{ order.add("ADDED"+"亦"+updatedFile.get(i)); index++; //keeps it at the end } } // increases index if a REMOVE is found if(index != order.size() && order.get(index).contains("REMOVED")) index++; } } //Starts the ordered array with all the lines from the first file, checks if they are the same or need to be removed private static ArrayList<String> getStartingOrder(ArrayList<String> StartingFile, ArrayList<String> updatedFile) { ArrayList<String> order = new ArrayList<>(); //foreach string in the first file passed to it, use a chinese character so that i can split type from line later on for (String x: StartingFile){ if(updatedFile.contains(x)) order.add("SAME"+"亦"+x); else order.add("REMOVED"+ "亦" + x); } return order; } //reads the file from the file name passed to it, returns a string arraylist of each line private static ArrayList<String> getContents(String fileName) throws IOException { ArrayList<String> returnValues = new ArrayList<>(); BufferedReader reader = new BufferedReader(new FileReader(fileName)); while(reader.ready()) returnValues.add(reader.readLine()); reader.close(); return returnValues; } public static enum Type { ADDED, // New line added REMOVED, // Line deleted SAME // No change } public static class LineItem { public Type type; public String line; public LineItem(Type type, String line) { this.type = type; this.line = line; } } }

Comments (6)

Popular
New
Old

You must be signed in to leave a comment

Sanjeevkumar

Level 22 , Mumbai, India

15 August 2020, 05:18

Guadalupe i have one doubt if the lines are different For REMOVED: should i move the counter in original by 1 step or upto the last element of original list. and for ADDED : should i move the counter in updated by 1 step or upto the last elment of update list . what should i do?

Ivaylo Trifonov

Level 22 , Madrid, Spain

1 November 2019, 08:05

I found Your way to test the code, with the boolean check, very convenient. I use commenting/deleting the lines of code which I use to test the program, but sometimes I just forget to comment some lines of code and.... I get an error when I submit the code for check :(

Guadalupe Gagnon

Level 37 , Tampa, United States

24 December 2018, 20:34

Solved it. I was over thinking it and the key was the restriction that "The ADDED and REMOVED labels can't be used consecutively". This means that when you either ADDED or REMOVED a line (and there are still lines to be parsed), then the next one has to be SAME. Basically you have to test each line of the file and if they are the same:

lines.add(new LineItem(Type.SAME, theFullLine));

and move your counter for each by 1 if they are different check to see if the next line from the original matches, if true:

lines.add(new LineItem(Type.REMOVED, theFullLine));

and move only the counter from file 1 and if false

lines.add(new LineItem(Type.ADDED, theFullLine));

and move only the counter from the second file

Weichen Ouyang

Level 25 , San Jose, United States

20 September 2019, 01:04

Thanks for the hint, man. You are superb.

Dawid

Level 28

1 September 2020, 20:49

Could you write this algorithm more precisely or give its code? Because when I try to apply it, I get not entirely correct results.

Dan

Level 26 , Clarksville, United States

Expert

6 August 2021, 16:20

This right here is the key. You helped me a ton with this hint. With your help, I finally solved this problem after spending far too long on it.