package com.crack;
import java.util.HashMap;
import java.util.HashSet;
import java.util.LinkedList;
import java.util.Queue;
import java.util.Set;
import java.util.TreeMap;
import java.util.TreeSet;
public class GetOneEditWords {
Set<String> getOneEditWords(String word)
{
Set<String> words=new TreeSet<String>();
for(int i=0;i<word.length();i++)
{
char[] wordarray=word.toCharArray();
for(char c='A';c<='Z';c++)
{
if(wordarray[i]!=c)
{
wordarray[i]=c;
words.add(new String(wordarray));
}
}
}
return words;
}
LinkedList<String> transform(String startword,String stopword,Set<String> dictionary)
{
startword=startword.toUpperCase();
stopword=stopword.toUpperCase();
Queue<String> q=new LinkedList<String>();
Set<String> visited=new HashSet<String>();
TreeMap<String,String> table=new TreeMap<String,String>();
q.add(startword);
visited.add(startword);
while(!q.isEmpty())
{
String w=q.poll();
for(String v:getOneEditWords(w))
{
if(v==stopword)
{
LinkedList<String> list=new LinkedList<String>();
list.add(v);
while(w!=null)
{
w=table.get(w);
list.add(0,w);
}
return list;
}
if(dictionary.contains(v))
{
if(!visited.contains(v))
{
q.add(v);
visited.add(v);
table.put(v,w);//v的前驱结点是w
}
}
}
}
return null;
}
}
import java.util.HashMap;
import java.util.HashSet;
import java.util.LinkedList;
import java.util.Queue;
import java.util.Set;
import java.util.TreeMap;
import java.util.TreeSet;
public class GetOneEditWords {
Set<String> getOneEditWords(String word)
{
Set<String> words=new TreeSet<String>();
for(int i=0;i<word.length();i++)
{
char[] wordarray=word.toCharArray();
for(char c='A';c<='Z';c++)
{
if(wordarray[i]!=c)
{
wordarray[i]=c;
words.add(new String(wordarray));
}
}
}
return words;
}
LinkedList<String> transform(String startword,String stopword,Set<String> dictionary)
{
startword=startword.toUpperCase();
stopword=stopword.toUpperCase();
Queue<String> q=new LinkedList<String>();
Set<String> visited=new HashSet<String>();
TreeMap<String,String> table=new TreeMap<String,String>();
q.add(startword);
visited.add(startword);
while(!q.isEmpty())
{
String w=q.poll();
for(String v:getOneEditWords(w))
{
if(v==stopword)
{
LinkedList<String> list=new LinkedList<String>();
list.add(v);
while(w!=null)
{
w=table.get(w);
list.add(0,w);
}
return list;
}
if(dictionary.contains(v))
{
if(!visited.contains(v))
{
q.add(v);
visited.add(v);
table.put(v,w);//v的前驱结点是w
}
}
}
}
return null;
}
}