Sorting&Searching 基于变位词的字符串数组排序 @CareerCup

两种排序结果不一样。。。

1 实现Comparator接口的compare方法，在里面先把每个string都排序一遍，然后再比较

2 用一个Hashtable<String, LinkedList<String>>的结构，String为排序后的确定的string，LL里面装着各种anagram的变种

package Sorting_Searching;

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

import CtCILibrary.AssortedMethods;

/**
 * Write a method to sort an array of strings so that all the anagrams are next
 * to each other.
 * 
 * 译文：
 * 
 * 写一个函数对字符串数组排序，使得所有的变位词都相邻。
 * 
 */
public class S11_2 {
	public static void main(String[] args) {
		String[] array1 = { "apple", "banana", "carrot", "ele", "duck", "papel",
				"tarroc", "cudk", "eel", "lee" };
		System.out.println(AssortedMethods.stringArrayToString(array1));
		Arrays.sort(array1, new AnagramComparator());
		System.out.println(AssortedMethods.stringArrayToString(array1));
		
		String[] array2 = { "apple", "banana", "carrot", "ele", "duck", "papel",
				"tarroc", "cudk", "eel", "lee" };
		sort(array2);
		System.out.println(AssortedMethods.stringArrayToString(array2));
	}
	
	static class AnagramComparator implements Comparator<String>{

		@Override
		public int compare(String s1, String s2) {
			String sorted1 = sortChars(s1);
			String sorted2 = sortChars(s2);
			return sorted1.compareTo(sorted2);
		}
	}
	
	public static String sortChars(String s){
		char[] ch = s.toCharArray();
		Arrays.sort(ch);
		return new String(ch);
	}
	
	public static void sort(String[] array) {
		Hashtable<String, LinkedList<String>> hash = new Hashtable<String, LinkedList<String>>();
		
		// Group words by anagram
		for(String s : array){
			String key = sortChars(s);
			if(!hash.containsKey(key)){
				hash.put(key, new LinkedList<String>());
			}
			LinkedList<String> anagrams = hash.get(key);
			anagrams.push(s);
		}
		
		// Convert hash table to array
		int index = 0;
		for(String key : hash.keySet()){
			LinkedList<String> anagrams = hash.get(key);
			for(String t : anagrams){
				array[index++] = t;
			}
		}
	}
	
}