Word Ladder解决程序坏了

Question

我正在尝试制作一个程序，在标准词典文本文件中的任意两个单词之间打印出一个单词梯形图，但它仍然卡在一个单词上。当我尝试“天使”和“恶魔”时，它总是“蔬菜”。

以下是代码：

import java.util.Arrays;
import java.util.ArrayList;
import java.util.Queue;
import java.util.LinkedList;
import java.util.Stack;
class WordLadder
{
    static ArrayList words=new ArrayList();
    public static void main(String[] args)
    {
        EasyReader dictFile=new EasyReader("C:\\dict.txt");
        EasyReader input=new EasyReader();
        String o;
        while ((o = dictFile.readWord()) != null)
        {
            words.add(o.toLowerCase());
        }
        System.out.println("What is the starting word?");
        String start=input.readLine();
        System.out.println("What is the ending word?");
        String end=input.readLine();
        if(start.length()!=end.length())
        {
            System.out.println("The words have to be the same length!");
            System.exit(0);
        }
        boolean isfound=false;
        LinkedList q = new LinkedList();
        LinkedList procq = new LinkedList();
        Stack starter=new Stack();
        starter.push(start);
        q.add(starter);
        ArrayList used=new ArrayList();
        used.add(start);
        while(!isfound)
        {
            Stack process=(Stack)q.removeLast();
            System.out.println("finding one-offs for "+process.peek());
            ArrayList oneoffs=findOneOffWords(process.peek().toString(), used);
            System.out.println(oneoffs);
            if(!oneoffs.isEmpty())
            {
                for(int i=0;i<oneoffs.size();i++)
                {
                    Stack toproc=process;
                    System.out.println("processing stack: "+toproc);
                    toproc.add(oneoffs.get(i));
                    while(q.removeFirstOccurrence((Object)toproc))
                    {
                    }
                    boolean isused=false;
                    for (Object temp : used)
                    {
                        if(toproc.peek().toString().equalsIgnoreCase(temp.toString()))
                        {
                            isused=true;
                        }
                    }
                    if(!isused)
                    {
                        q.add(toproc);
                    }
                    used.add(oneoffs.get(i));
                    if(toproc.peek().toString().equalsIgnoreCase(end))
                    {
                        System.out.println("found solution!");
                        while(!toproc.empty())
                        {
                            System.out.println(toproc.pop().toString());
                        }
                    }
                }
            }
        }
    }
    public static ArrayList findOneOffWords(String word, ArrayList used)
    {
        ArrayList oneoff=new ArrayList();
        for(int i=0;i<167964;i++)
        {
            if(word.length()==words.get(i).toString().length())
            {
                int counter=0;
                for(int h=0; h<word.length(); h++)
                {
                    if(!word.substring(h,h+1).equalsIgnoreCase(words.get(i).toString().substring(h,h+1)))
                    {
                        counter++;
                    }
                }
                boolean isused=false;
                for (Object temp : used)
                {
                    if(words.get(i).toString().equalsIgnoreCase(temp.toString()))
                    {
                        isused=true;
                    }
                }
                if(counter==1&&isused==false)
                {
                    oneoff.add(words.get(i));
                }
            }
        }
        return oneoff;
    }
}