I need some clarifications

Question about the task

Under discussion

After reading the asked questions about this topic I understand this: 1. The resulting chain mustn't be the longest 2. I assume that the chaining is at the beginning or at the end. I tested my code with the following input: CaaT Okinawa Washington Auckland Kalamazoo zoooZ zooe Norfolk The output was: Washington Norfolk Kalamazoo Okinawa Auckland Maybe I am missing something about the conditions of validation. Can I get a hint?

In the main method, read the name of a file that contains words separated by spaces from the console.
In the getLine method, use StringBuilder to order all the words as follows: the last letter of a word must match the first letter of the next word (ignore case).
Each word should be used once.
The getLine method can return any variant.
Separate words with a space.
Display the resulting string on the screen.

Example input file:

Okinawa Washington Auckland Kalamazoo Norfolk

Result:

Washington Norfolk Kalamazoo Okinawa Auckland

Requirements:

The main method must read the filename from the keyboard.
There should not be static fields in the Solution class.
The getLine method must use StringBuilder.
The getLine method must return an empty string (an empty StringBuilder) if it is not passed arguments (words).
The getLine method must not change the arguments (words).
All words passed to the getLine method must be included in the resulting string, if possible.
The screen output must match the task conditions.

package com.codegym.task.task22.task2209; /* Make a word chain */ import java.io.BufferedReader; import java.io.FileReader; import java.io.IOException; import java.io.InputStreamReader; import java.util.*; public class Solution { public static void main(String[] args) throws IOException { // ... BufferedReader reader = new BufferedReader(new InputStreamReader(System.in)); String fileName = reader.readLine(); reader.close(); BufferedReader reader1 = new BufferedReader(new FileReader(fileName)); ArrayList<String> list = new ArrayList<>(); String data; while (((data = reader1.readLine()) != null)) { String[] array = data.trim().split(" "); list.addAll(Arrays.asList(array)); } String[] words = list.toArray(new String[0]); StringBuilder result = getLine(words); System.out.println(result.toString()); } public static StringBuilder getLine(String... words) { StringBuilder builder = new StringBuilder(""); //I add all the words into an ArrayList if(words.length!=0) { ArrayList<String> list1 = new ArrayList<>(); Collections.addAll(list1, words); //here I want to remove all the words that don't have a chained word for (int i = 0; i < list1.size(); ) { //I set a counter which is the size of the list int counter = list1.size(); //I set a second counter which will increment if no match is found int secondCounter = 0; //I start with the word at index i and I will compare the first and last letter //of the word with the first and last letter of the hole list String firstWord = list1.get(i); String wordFirstChar = String.valueOf(firstWord.charAt(0)); String wordLastChar = String.valueOf(firstWord.charAt(firstWord.length() - 1)); for (int j = 0; j < list1.size(); j++) { //the second word, the first letter and the last letter initialization String secondWord = list1.get(j); String secondWordFirstChar = String.valueOf(secondWord.charAt(0)); String secondWordLastChar = String.valueOf(secondWord.charAt(secondWord.length() - 1)); //if there is no match, I increment the second counter if (!wordLastChar.equalsIgnoreCase(secondWordFirstChar) && (!wordFirstChar.equalsIgnoreCase(secondWordLastChar))) { secondCounter++; } } //I check to see if the first and last letter of the word are equal //thus eliminating words like "Americana" who don't match other words //but match it and not incrementing if (wordFirstChar.equalsIgnoreCase(wordLastChar)) { secondCounter++; } //I check if the initial counter is equal to the second counter //If it is equal it means that we have iterated trough the hole list and //didn't find a match. If true we remove the element from the list //if not, we increment i. if (counter == secondCounter) { list1.remove(i); } else { i++; } } //I start the builder with the first element of the list. builder = new StringBuilder(list1.get(0)); //I declare a boolean breacker to exit the outher loop boolean breacker = false; for (int i = 0; i < list1.size(); ) { //I declare the first word as the hole builder and //initialize the first and last letter String firstWord = builder.toString(); String wordFirstChar = String.valueOf(firstWord.charAt(0)); String wordLastChar = String.valueOf(firstWord.charAt(firstWord.length() - 1)); //I loop trough the hole loop to find a match of the first letter or the last letter for (int j = 0; j < list1.size(); j++) { String secondWord = list1.get(j); String secondWordFirstChar = String.valueOf(secondWord.charAt(0)); String secondWordLastChar = String.valueOf(secondWord.charAt(secondWord.length() - 1)); //If I find a match on the last letter I append the word to the builder //remove the element from the list and break if (wordLastChar.equalsIgnoreCase(secondWordFirstChar)) { builder.append(" ").append(secondWord); list1.remove(j); break; //If I find a match on the first letter I insert the word to the builder //at index 0, remove the element from the list and break } else if (wordFirstChar.equalsIgnoreCase(secondWordLastChar)) { builder.insert(0, secondWord + " "); list1.remove(j); break; } //if I loop trough the hole list and don't find a match for the chain //this means that there is no more word to add if (j == list1.size() - 1) { //I set the breacker to true breacker = true; } } //I breack the outer loop if (breacker) { break; } } } return builder; } }

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Guadalupe Gagnon

Level 37 , Tampa, United States

14 December 2023, 14:14

I got a weird result when I tested the code by passing ("hannah", "hannah") to the getLine() method.

catalin1989

Level 37 , Romania

14 December 2023, 15:00

Thanx for the feedback, I tested it with the input: CaaT Okinawa Washington hannah Auckland Kalamazoo zoooZ zooe hannah Norfolk and the result was: Washington Norfolk Kalamazoo Okinawa Auckland. When I tested it with ("hannah", "hannah"), I got hannah hannah hannah. I changed at line 81 the value of i from 0 to 1. and the result was hannah, hannah. But still it isn't validating.

Guadalupe Gagnon

Level 37 , Tampa, United States

14 December 2023, 17:08

I made that change and then tested the code with "hannah" "hannah" "home"

catalin1989

Level 37 , Romania

14 December 2023, 18:54

Thank you for the input. I modified line 81 again changed i starting value to 0. On line 78 I removed from the list the starting word in the String Builder. The line is this: list1.remove(0); I tested the code with the input "hannah" "hannah", the output was "hannah hannah" I testet the code with the input "hannah" "hannah" "home", the output was "hannah hannah home". The code is still not validating. It is getting frustrating. I really apreciate you effort.

Guadalupe Gagnon

Level 37 , Tampa, United States

14 December 2023, 19:00

I think your problem now is in the case that only 1 word is passed into the method, or multiple words are passed in but no connections can be made with them. The method should still return something other than a blank String in these cases.

Guadalupe Gagnon

Level 37 , Tampa, United States

14 December 2023, 19:20

I really like how you commented all your code. In the real world you don't have to be that detailed, but when you are learning it is a good habit to do. When I start a project, before I even code, I write a whole bunch of notes describing exactly what I hope to achieve with my code. Almost like a step by step guide. After I am satisfied with my noted approach I start coding. That doesn't mean my code is correct the first time as I will run into a ton of problems I never considered before I started testing the actual code, but it is a good way to start.

catalin1989

Level 37 , Romania

14 December 2023, 20:08

So, at line 34 I added if(words.length==1){ builder.append(words[0]); return builder; }, to check if I get only one word, in this case I append to the builder the word and I return it. At line 81, after I delete all the words from the list that don't have a match I checked if the list is empy if(list1.isEmpty()){ builder.append(words[0]); return builder; }. In this case I append to the builder the first word. It doesent matther the word, because the list if full of words that don't chain. Tested it with "hannah". The output was "hannah". Tested it with "something", "hannah". The output was "something". Still didn't pass. I think I will study the CodeGym Answer.

catalin1989

Level 37 , Romania

14 December 2023, 20:12

Thanx for the feedback. I read a lot that the readability of the code is very important. And as my code is a bit long, I tought that it was easyer for someone else to read it if I comment what important lines do, or to explain the logic. As you mentioned about writing notes, I think that every software project starts on the drawing bord, where you draw what object you need, what are the characteristics of those objects, how they interact with one another.