com.javarush.task.task22.task22091

package com.javarush.task.task22.task2209;

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

/*
Составить цепочку слов
*/

public class Solution {
    public static void main(String[] args) throws IOException {
       /*BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
        BufferedReader fr = new BufferedReader(new FileReader(reader.readLine()));
        String txt;
        String stroka="";
        while ((txt=fr.readLine())!=null){
            stroka+=txt+" ";
        }
        reader.close();
        fr.close();
        StringBuilder result = getLine(stroka);
        System.out.println(result.toString());*/
        System.out.println(getLine("alpha elephant kick linea android eels kill sum eye spud drink even bee dad num tea test sims apple mob mate"));
        System.out.println(getLine("Абинск Кабул Киров Ватикан Называевск"));
        System.out.println(getLine("АГ ЖЖ ДБ ЕЕ АБ ЖЕ БВ ГД ДЕ ЕЖ ЖГ ГЖ ЕЕ ЕД ВА"));
        System.out.println(getLine("bee elephant num apple mob eels elain tea sum mate"));
        System.out.println(getLine("sum eels mate num bee mob even eye"));
        System.out.println(getLine("mate bee dad android sum drink kill elephant linea apple tea even num eels mob"));
        System.out.println(getLine("Кабул Абинск Киров Ватикан Называевск"));
    }

    public static StringBuilder getLine(String... words) {
        StringBuilder builder = new StringBuilder();
        if (words == null || words.length == 0) {return builder;}
        String[] a = Arrays.asList(words).get(0).split(" ");
        ArrayList<String> stringArrayList = new ArrayList<>();
        for (int i = 0; i < a.length; i++) {
            stringArrayList.add(a[i]);
        }
        if (a.length==1 || words[0].equals("")) {return builder.append(words[0]);}
        List<String> list = new ArrayList<>();

        builder.append(stringArrayList.get(0));
        stringArrayList.remove(0);
        int countWhile = 0;
        while (stringArrayList.size()>1){
            while (true) {
                if (countWhile==stringArrayList.size()){
                    countWhile = 0;
                    break;
                }
                char last = builder.toString().toLowerCase().charAt(builder.length()-1);
                char first = stringArrayList.get(countWhile).toLowerCase().charAt(0);
                if (last == first){
                    builder.append(" "+stringArrayList.get(countWhile));
                    stringArrayList.remove(countWhile);
                    countWhile=0;
                }else countWhile++;
            }
            while (true)
            {
                if (countWhile == stringArrayList.size()){
                    countWhile= 0 ;
                    break;
                }
                char last = stringArrayList.get(countWhile).toLowerCase().charAt(stringArrayList.get(countWhile).length()-1);
                char first = builder.toString().toLowerCase().charAt(0);
                if (last == first){
                    builder.insert(0,stringArrayList.get(countWhile)+" ");
                    stringArrayList.remove(countWhile);
                    countWhile = 0;
                }else countWhile++;
            }
            list.add(0,builder.substring(builder.lastIndexOf(" ")));
            builder.delete(builder.lastIndexOf(" "), builder.length());
        }
        for (int i = 0; i <list.size() ; i++) {
            builder.append(list.get(i));
        }
        return builder;
    }
}