CC150 - 11.2

Question:

Write a method to sort an array of strings so that all the anagrams are next to each other.

 package POJ;

 import java.util.Arrays;
 import java.util.Comparator;
 import java.util.Hashtable;
 import java.util.LinkedList;
 import java.util.List;

 public class Main {

     /**
      *
      * 11.2 Write a method to sort an array of strings so that all the anagrams are next to each other.
      *
      */
     public static void main(String[] args) {
         Main so = new Main();
     }

     public void sort(String[] list) {
         Hashtable<String, LinkedList<String>> ht = new Hashtable<String, LinkedList<String>>();
         AnagramCompare ac = new AnagramCompare();
         for (String s : list) {
             String key = ac.sortChars(s);
             if (!ht.contains(key)) {
                 ht.put(key, new LinkedList<String>());
             }
             LinkedList<String> anagrams = ht.get(key);
             anagrams.add(s);
         }
         int index = 0;
         for (String s : ht.keySet()) {
             LinkedList<String> tempList = ht.get(s);
             for (String t : tempList) {
                 list[index] = t;
                 index++;
             }
         }
     }
 }

 class AnagramCompare implements Comparator<String> {
     public String sortChars(String s1) {
         char[] temp = s1.toCharArray();
         Arrays.sort(temp);
         return new String(temp);
     }

     @Override
     public int compare(String o1, String o2) {
         // TODO Auto-generated method stub
         return sortChars(o1).compareTo(sortChars(o2));
     }
 }

注意：comparator的重写方法！！！