贪心：Huffman

package com.iteye.caoruntao.huffman;

import java.util.Comparator;
import java.util.PriorityQueue;

/**
 * @author caoruntao
 *
 */
public class Huffman {

	private PriorityQueue<Character> characters;
	
	
	public Huffman(Character[] characers){
		this.characters = new PriorityQueue<Character>(6,new Comparator<Character>(){

			@Override
			public int compare(Character a, Character b) {
				return (a.getFrequency() - b.getFrequency());
			}
		});
		for (Character character : characers) {
			this.characters.add(character);
		}
	}
	
	public void computeHuffman(){
		for(int i = 1; i < 6; i++){
			Character a = this.characters.poll();
			Character b = this.characters.poll();
			Character newNode = new Character(a.getFrequency()+b.getFrequency());
			newNode.setLeftSon(a);
			newNode.setRightSon(b);
			this.characters.add(newNode);
		}
	}
	
	public void printResult(Character c){
		if(c.getLeftSon() != null){
			System.out.print("0 ");
			printResult(c.getLeftSon());
		}
		if(c.getRightSon() != null){
			System.out.print("1 ");
			printResult(c.getRightSon());
		}
		if(c.getLeftSon() == null && c.getRightSon() == null){
			System.out.print(":"+c.getX());
			System.out.println();
		}
	}
	
	
	static class Character{
		private int frequency;
		private char x;
		private Character leftSon;
		private Character rightSon;
		
		public Character(int frequency, char x){
			this.frequency = frequency;
			this.x = x;
		}

		public Character(int frequency){
			this.frequency = frequency;
		}
		
		public Character getLeftSon() {
			return leftSon;
		}

		public void setLeftSon(Character leftSon) {
			this.leftSon = leftSon;
		}

		public Character getRightSon() {
			return rightSon;
		}

		public void setRightSon(Character rightSon) {
			this.rightSon = rightSon;
		}

		public int getFrequency() {
			return frequency;
		}

		public char getX() {
			return x;
		}
		
		public String toSring(){
			return this.x + " " + this.frequency;
		}
	}
	
	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		char[] testChS = new char[]{'f','e','c','b','d','a'};
		int[] testChF = new int[]{5,9,12,13,16,45};
		Character[] ChS = new Character[6];
		for(int i=0; i<6; i++){
			Huffman.Character c = new Huffman.Character(testChF[i],testChS[i]);
			ChS[i] = c;
		}
		Huffman huffman = new Huffman(ChS);
		huffman.computeHuffman();
		huffman.printResult(huffman.characters.poll());
	}

}