Just Understanding what they are looking for, Is this it?

Question about the task

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Java Core, Level 9, Lesson 11

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I think this is what they are looking for. Obviously the result would be in the proper format...

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.BufferedReader; import java.io.FileReader; import java.io.InputStreamReader; import java.util.ArrayList; import java.util.List; /* Tracking changes */ public class Solution { public static List<LineItem> lines = new ArrayList<>(); public static void main(String[] args) throws Exception { BufferedReader re = new BufferedReader(new InputStreamReader(System.in)); String fileName1 = re.readLine(); String fileName2 = re.readLine(); //String fileName1 = "C:\\Users\\Alfred\\Documents\\CodeGym Data Files for exercizes\\File1.txt"; //String fileName2 = "C:\\Users\\Alfred\\Documents\\CodeGym Data Files for exercizes\\File2.txt"; re.close(); BufferedReader flb1 = new BufferedReader(new FileReader(fileName1)); ArrayList<String> file1 = new ArrayList<String>(); while (flb1.ready()) { String line = flb1.readLine(); file1.add(line); } flb1.close(); BufferedReader flb2 = new BufferedReader(new FileReader(fileName2)); ArrayList<String> file2 = new ArrayList<String>(); while (flb2.ready()) { String line2 = flb2.readLine(); file2.add(line2); } file2.add(""); file2.add(""); file2.add(""); file2.add(""); flb2.close(); boolean ck = false; // ++++++++++++++++++++++++++ test to see what is in arrays ++++++++++++++++++++++++ /* for (int i = 0; i < file1.size(); i++) { System.out.println(i + " " + file1.get(i)); } System.out.println(); System.out.println("---------------------"); System.out.println(); for (int i = 0; i < file2.size(); i++) { System.out.println(i + " " + file2.get(i)); } System.out.println(); System.out.println(); */ // !!!!!!!!!!!!!!!!!!!!!!!!!!!!! THE CRAZY STARTS HERE !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! for (int i = 0; i < file1.size(); i++) { // ________________________ Print out info at the beginning For each loop ..................... /* System.out.println("--------------------------------------"); System.out.println("Loop i = " + i); System.out.println(); System.out.println("Original File :" + file1.get(i)); System.out.println("New File :" + file2.get(i)); System.out.println(); */ // ---------------------- L1(i) AND L2(i) MATCH ------------ if (file1.get(i).equals(file2.get(i))) { lines.add(new LineItem(Type.SAME, file1.get(i))); } else { // ------------ L1(i) AND L2(i) DONT MATCH ------------ ck = false; for (int j = i; j < file2.size(); j++) if (file1.get(i).equals(file2.get(j))) { ck = true; } if (ck) { ck = false; for (int j = i; j < file1.size(); j++) { if (file2.get(i).equals(file1.get(j))) { ck = true; } } if (ck) { if (!file2.get(i).equals("")){ lines.add(new LineItem(Type.SAME, file2.get(i)));} } else { ck = false; for (int j = 0; j < file1.size(); j++) { if (file2.get(i).equals(file1.get(j))) { ck = true; } } if (!ck) { lines.add(new LineItem(Type.ADDED, file2.get(i))); } } if (!file1.get(i).equals("")) { lines.add(new LineItem(Type.SAME, file1.get(i))); } } else { ck = false; for (int j = 0; j < file2.size(); j++) if (file1.get(i).equals(file2.get(j))) { ck = true; } if (!ck) { lines.add(new LineItem(Type.REMOVED, file1.get(i))); } // ck = false; for (int j = i; j < file1.size(); j++) if (file2.get(i).equals(file1.get(j))) { ck = true; } if ((ck == true) && (!file2.get(i).equals(""))) { lines.add(new LineItem(Type.SAME, file2.get(i))); } else { if (!file2.get(i).equals("")) { ck = false; for (int j = 0; j < file1.size(); j++) { if (file2.get(i).equals(file1.get(j))) { ck = true; } } if (!ck) { lines.add(new LineItem(Type.ADDED, file2.get(i))); } } } } } /* // ------------ Printing out results at end of each loop ______________ System.out.println("List finish Contents:"); for (int l = 0; l < lines.size(); l++) { System.out.println(lines.get(l).type + " " + lines.get(l).line); } */ } // --------------------------- // end of loop ------------- } 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; } } } /* // ---------------------- L1(I) AND L2(I) MATCH ------------ if (file1.get(i).equals(file2.get(i))) { lines.add(new LineItem(Type.SAME, file1.get(i))); System.out.println("Break at 1"); System.out.println(); System.out.println("List finish Contents:"); for (int l = 0; l < lines.size(); l++){ System.out.println(lines.get(l).type +" "+lines.get(l).line); } continue; } // ____________ i = 0 first line --------------------- if (i==0){ if (!file1.get(i).equals(file2.get(i))) { lines.add(new LineItem(Type.REMOVED, file1.get(i))); } if (file1.get(i).equals(file2.get(i+1))) { lines.add(new LineItem(Type.SAME, file2.get(i))); lines.add(new LineItem(Type.SAME, file1.get(i))); } System.out.println("Break at 00"); System.out.println(); System.out.println("List finish Contents:"); for (int l = 0; l < lines.size(); l++){ System.out.println(lines.get(l).type +" "+lines.get(l).line); } continue; } // ----------- fl1 matches next fl2 Line B2----------------- if (file1.get(i).equals(file2.get(i + 1))) { lines.add(new LineItem(Type.ADDED, file2.get(i))); if ((!file1.get(i - 1).equals(file2.get(i))) && (!file1.get(i + 1).equals(file2.get(i)))) { // fl2 no match fl1 + 1 lines.add(new LineItem(Type.SAME, file1.get(i))); } System.out.println("Break at 2"); System.out.println(); System.out.println("List finish Contents:"); for (int l = 0; l < lines.size(); l++){ System.out.println(lines.get(l).type +" "+lines.get(l).line); } continue; } // -------------------- fl1 matches previous fl2 B3 --------------- /* if ((file1.get(i).equals(file2.get(i - 1))) || (file1.get(i).equals(file2.get(i - 2)))){ lines.add(new LineItem(Type.SAME, file1.get(i))); if ((!file1.get(i - 1).equals(file2.get(i))) || (!file1.get(i + 1).equals(file2.get(i)))){ lines.add(new LineItem(Type.ADDED, file2.get(i))); } ____________________________________________________________________ boolean ck1 = false; for (int j = 0; j < file2.size(); j++) if (file1.get(i).equals(file2.get(j))){ ck1 = true; } if ( ck1 == true) { lines.add(new LineItem(Type.SAME, file1.get(i))); // check to see if FL2(i) is in Fl1 === boolean ck2 = false; for (int j = 0; j < file1.size(); j++) if (file2.get(i).equals(file1.get(j))){ ck2 = true; } if ((!ck2 == true) && (!file2.get(i).equals(""))){ lines.add(new LineItem(Type.ADDED, file2.get(i))); } System.out.println("Break at 3"); System.out.println(); System.out.println("List finish Contents:"); for (int l = 0; l < lines.size(); l++){ System.out.println(lines.get(l).type +" "+lines.get(l).line); } continue; } // ___________ FL1 (i) matches FL2 (i-2) ---------------- if (file1.get(i).equals(file2.get(i - 2))) { lines.add(new LineItem(Type.SAME, file1.get(i))); System.out.println("FL1 (i) matches FL2 (i-2)"); System.out.println(); System.out.println("List finish Contents:"); for (int l = 0; l < lines.size(); l++){ System.out.println(lines.get(l).type +" "+lines.get(l).line); } continue; } // --------------- fl1 matches no line ------------------------ boolean ck5 = false; for (int j = 0; j < file2.size(); j++) if (file1.get(i).equals(file2.get(j))){ ck5 = true; } if ( ck5 == false) { lines.add(new LineItem(Type.REMOVED, file1.get(i))); System.out.println(" FL1 matches no line"); System.out.println(); System.out.println("List finish Contents:"); for (int l = 0; l < lines.size(); l++) { System.out.println(lines.get(l).type + " " + lines.get(l).line); } } +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ */ /* public class Solution { public static List<LineItem> lines = new ArrayList<>(); public static void main(String[] args) throws Exception { BufferedReader re = new BufferedReader(new InputStreamReader(System.in)); // String fileName1 = re.readLine(); //String fileName2 = re.readLine(); String fileName1 = "C:\\Users\\Alfred\\Documents\\CodeGym Data Files for exercizes\\File1.txt"; String fileName2 = "C:\\Users\\Alfred\\Documents\\CodeGym Data Files for exercizes\\File2.txt"; re.close(); BufferedReader flb1 = new BufferedReader(new FileReader(fileName1)); ArrayList<String> file1 = new ArrayList<String>(); while (flb1.ready()) { String line = flb1.readLine(); file1.add(line); } flb1.close(); BufferedReader flb2 = new BufferedReader(new FileReader(fileName2)); ArrayList<String> file2 = new ArrayList<String>(); while (flb2.ready()) { String line2 = flb2.readLine(); file2.add(line2); } file2.add(""); file2.add(""); flb2.close(); // test to see what is in arrays for (int i = 0; i < file1.size(); i++) { System.out.println(i + " " + file1.get(i)); } System.out.println(); System.out.println("---------------------"); System.out.println(); for (int i = 0; i < file2.size(); i++) { System.out.println(i + " " + file2.get(i)); } System.out.println(); System.out.println("========================================================="); System.out.println(); Type lastType = Type.SAME; int j = 0; // THE CRAZY STARTS HERE !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! for (int i = 0; i < file1.size(); i++) { System.out.println("--------------------------------------"); System.out.println("start of loop " + i + ", Last type recorded " + lastType); System.out.println(); switch (lastType) { case SAME: {System.out.println("SAME CASE---"); if ((file1.get(i).equals(file2.get(i))) || (file1.get(i).equals(file2.get(i - 1))) || (file1.get(i).equals(file2.get(i )))){ lines.add(new LineItem(Type.SAME, file1.get(i))); System.out.println("SAME written to lines"); j++; lastType = Type.SAME; }else { if (!file2.get(i).equals(file1.get(i - 1)) && (!file2.get(i).equals(file1.get(i + 1)))) { lines.add(new LineItem(Type.ADDED, file2.get(i))); System.out.println("ADDED written to lines"); j++; lastType = Type.ADDED; } if ((!file1.get(i).equals(file2.get(i))) && ((!file1.get(i).equals(file2.get(i + 1))) && (!file1.get(i).equals(file2.get(i - 1))))) { lines.add(new LineItem(Type.REMOVED, file1.get(i))); System.out.println("REMOVED written to lines"); lastType = Type.REMOVED; break; } } break; } case REMOVED: {System.out.println("REMOVED CASE----"); lines.add(new LineItem(Type.SAME, file1.get(i))); System.out.println("SAME written to lines"); lastType = Type.SAME; if ((!file2.get(i).equals(file1.get(i))) || (!file2.get(i).equals(file1.get(i + 1))) || (!file2.get(i).equals(file1.get(i - 1)))) { lines.add(new LineItem(Type.ADDED, file2.get(i + 1))); lastType = Type.ADDED; } break; } case ADDED: {System.out.println("ADDED CASE---"); lines.add(new LineItem(Type.SAME, file1.get(i-1))); System.out.println("SAME written to lines"); i--; lastType = Type.SAME; break; } } System.out.println(); System.out.println("List Contents:"); for (int l = 0; l < lines.size(); l++){ System.out.println(lines.get(l).type +" "+lines.get(l).line); } System.out.println(); System.out.println(); }// end of loop System.out.println("+++++++++ PRINT THAT MESS +++++++++"); System.out.println(); for (int l = 0; l < lines.size(); l++){ System.out.println(lines.get(l).type +" "+lines.get(l).line); } } 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 class Solution { public static List<LineItem> lines = new ArrayList<>(); public static void main(String[] args) throws Exception{ BufferedReader re = new BufferedReader(new InputStreamReader(System.in)); // String fileName1 = re.readLine(); //String fileName2 = re.readLine(); String fileName1 = "C:\\Users\\Alfred\\Documents\\CodeGym Data Files for exercizes\\File1.txt"; String fileName2 ="C:\\Users\\Alfred\\Documents\\CodeGym Data Files for exercizes\\File2.txt"; re.close(); BufferedReader flb1 = new BufferedReader(new FileReader(fileName1)); ArrayList<String> file1 = new ArrayList<String>(); while (flb1.ready()) { String line = flb1.readLine(); file1.add(line); } flb1.close(); BufferedReader flb2 = new BufferedReader(new FileReader(fileName2)); ArrayList<String> file2 = new ArrayList<String>(); while (flb2.ready()) { String line2= flb2.readLine(); file2.add(line2); } file2.add(""); file2.add(""); flb2.close(); // test to see what is in arrays for(int i =0;i<file1.size();i++){ System.out.println(i+" "+file1.get(i)); } System.out.println(); System.out.println("---------------------"); System.out.println(); for(int i =0;i<file2.size();i++){ System.out.println(i+" "+file2.get(i)); } System.out.println(); System.out.println("========================================================="); System.out.println(); int f=0; int ck = 0; for (int i = 0; i < file1.size(); i++){ System.out.println(i+" "+f); if (file1.get(i).equals(file2.get(i))) { if (f ==0 ) { lines.add(new LineItem(Type.SAME, file1.get(i))); } } else{ if (i+2+f < file2.size()) { if (file1.get(i).equals(file2.get(i + 1))) { lines.add(new LineItem(Type.ADDED, file2.get(i))); lines.add(new LineItem(Type.SAME, file2.get(i + 1))); f = 1; ck = 1; } else if (!file1.get(i).equals(file2.get(i + f))) { lines.add(new LineItem(Type.REMOVED, file1.get(i))); if (i != file2.size()-4) { lines.add(new LineItem(Type.SAME, file2.get(i + 1))); } f = 1; ck = 1; } } } if (i > (file2.size()-3) ){ lines.add(new LineItem(Type.REMOVED, file1.get(i))); } if ((i == (file2.size()-3)) && (ck == 0)){ lines.add(new LineItem(Type.SAME, file1.get(i))); ck=0; } if (i == (file2.size()-4) ){ lines.add(new LineItem(Type.ADDED, file2.get(i+1))); } System.out.println("_______________"); System.out.println(lines.size()); for (int l = 0; l < lines.size(); l++){ System.out.println(lines.get(l).type +" "+lines.get(l).line); } System.out.println(i+" "+f); } System.out.println("++++++++++++++++++++++++++++++++++++++++++"); for (int l = 0; l < lines.size(); l++){ System.out.println(lines.get(l).type +" "+lines.get(l).line); } } 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; } } } */

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AlfredW

Level 23 , Denver, United States

26 October 2020, 16:38

I finally got it. Much simplified as well. Being able to see what exactly they were looking for helped. But also recognizing that I needed to iterate through the arrays separately helped. Then to just go through the data line by line. I literally created a way to track thorough the decision process as it went along to see how to make it work. What a pain. But also a great learning experience. Did a crap load of coding before I got it. So lots of practice. It would be much easier though if they gave clearer conditions and example data.

Guadalupe Gagnon

Level 37 , Tampa, United States

26 October 2020, 16:56

I agree, I had a heck of a time completing this task back when I did. They have since updated the task requirements to make it easier to understand (the current requirements.....). The hardest task for me is 2025, which is coming up for you. They have since updated the requirements and added test code (inside the main) that wasn't there when I did the task, which does make it less of a headache, but it is still a tough one. It took me a week to complete that one and I literally had to find an algorithm online to get it to pass as I couldn't figure out why mine kept timing out on the validation.

Guadalupe Gagnon

Level 37 , Tampa, United States

26 October 2020, 13:50

It looks like you have the right idea, take a look at my comment on the task page just in case: task page