Checking if I am on the right track

Question about the task

Under discussion

It's outputting the correct code in my tests, but after seeing how many people are struggling with this, I know there must be more to it and I am missing something

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.util.ArrayList; import java.util.List; import java.util.zip.InflaterInputStream; /* Tracking changes */ public class Solution { public static List<LineItem> lines = new ArrayList<>(); //use insert in list to put in empty strings when a line is removed. //use a method to check which lines match. parameters will be a list? public static void main(String[] args) throws IOException { BufferedReader reader = new BufferedReader(new InputStreamReader(System.in)); String file1 = reader.readLine(); String file2 = reader.readLine(); reader.close(); ArrayList<String> list1 = new ArrayList<>(); ArrayList<String> list2 = new ArrayList<>(); //Needs to make the lists the same size by replacing empty array elements with empty //string or null if that works try (BufferedReader fileReader = new BufferedReader(new FileReader(file1))) { while (fileReader.ready()) { list1.add(fileReader.readLine()); } } try (BufferedReader fileReader2 = new BufferedReader(new FileReader(file2))){ while (fileReader2.ready()) { list2.add(fileReader2.readLine()); } } while (list1.size() != list2.size()) if (list1.size() > list2.size()) { list2.add(""); }else list1.add(""); int lineNumber = 1; for (int i = 0; i < list1.size(); i++) { if (lineNumber > 5) lineNumber = 0; if (list1.get(i).equals(list2.get(i))) { lines.add(new LineItem(Type.SAME,"line" + lineNumber)); } else if (list2.get(i).equals("")) { lines.add(new LineItem(Type.REMOVED,"line" + lineNumber)); } else if (list1.get(i).equals("")) { lines.add(new LineItem(Type.ADDED,"line" + lineNumber)); } else if (list1.contains(list2.get(i))) { lines.add(new LineItem(Type.REMOVED,"line" + lineNumber)); } else if (list2.contains(list1.get(i))) { lines.add(new LineItem(Type.ADDED,"line" + lineNumber)); } lineNumber++; } // for (LineItem x : lines) { // System.out.println(x.toString()); // } // for (int i = 0; i < lines.size(); i++) { // if (i == 0) { // boolean added = lines.get(i).getType().equals(Type.ADDED); // } // if (lines.get(i).getType().equals(Type.ADDED) && lines.get(i).getType().equals(Type.)) { // // } // } } 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; } // public Type getType() { // return type; // } // // public String toString() { // return String.format("LineItem{%s - %s}", type, line); // } } }

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Jaime Padilla

Level 22 , Chandler, United States

26 November 2022, 22:24

I figured it out!!! Thank you for the toString method. I don't think I could have done it without that. Also, I used your Tiger example text that you wrote in someone else's help comment. When I was able to get the Tiger example to print successfully, I thought I had it, only to find that something was still off. Which ended up being if the arrays were equal, my algorithm was creating an indexOutOfBounds error. Fixed that and it passed. They need to hire you to rewrite all the descriptions lol

Guadalupe Gagnon

Level 37 , Tampa, United States

25 November 2022, 05:38

useful

#1 The algorithm you have wont work. If a line is added then that means that it will be in file 2 but not int file 1. Therefore this bit of code will not work:

else if (list2.contains(list1.get(i))) {
   lines.add(new LineItem(Type.ADDED,"line" + lineNumber));

The same problem exists with the "removed" lines part of your algorithm because a removed line would be in file 1 but not in file 2. #2 The actual lines read in are supposed to be saved, not:

"line" + lineNumber

Look at the comment I added on the task page. It has a sample for file 1 and 2 with the correct output using that sample. It is a few comments down because a lot of people add a bunch of garbage instead of actual tips to help solve.