CC150

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！！！