堆排序

因为要观察稳定性，就自己定义数据元素

package sorted.util;
/*
 * Element用作排序算法的元素,value为其对应的值,index为其最开始时的下标
 * index主要用来观察稳定行
 */
public class Element {
	private int value ;
	private int index ;
	
	public int getValue() {
		return value;
	}
	public void setValue(int value) {
		this.value = value;
	}
	public int getIndex() {
		return index;
	}
	public void setIndex(int index) {
		this.index = index;
	}
	
}

具体的排序算法

package sorted;

import java.util.Arrays;
import java.util.Random;

import sorted.util.Element;

public class HeapSort {
	
	public static String formatter = "%3d";

	//建造大根堆,下标从0开始,左子节点为2*i+1,右子节点为2*(i+1)
	//对第i个节点进行堆排序
	public static void MaxHeapify(Element array[], int i){
		int left = 2*i+1;
		int right = 2*i+2;
		int max = i;
		//先判断左子节点
		if(left<array.length && array[max].getValue()<array[left].getValue()){
			max = left;
		}
		//需要确定右子节点是否存在
		if(right<array.length && array[max].getValue()<array[right].getValue()){
			max = right;
		}
		if(max!=i){
			Element tmp = array[max];
			array[max] = array[i];
			array[i] = tmp;
			MaxHeapify(array, max);
		}
	}
	public static void CreateHeap(Element array[]){
		int len = (array.length-1)/2;
		for(int i=len; i>=0; i--){
			MaxHeapify(array, i);
		}
	}
	
	public static Element[] HeapifySort(Element array[]){
		//result存放结果
		Element[] result = new Element[array.length];
		int index = 0;
		int len = array.length ;
		//取出堆顶,重复建堆
		for(int i=len-1; i>=0; i--){
			result[index] = array[0];
			index++;
			array[0] = array[array.length-1];
			array = Arrays.copyOfRange(array, 0, i);
			System.out.println("------"+i+"--------");
			print(array);
			System.out.println();
			MaxHeapify(array, 0);
		}
		return result;
	}
	
	public static void print(Element a[]){
		for(int i=0; i<a.length; i++)
			System.out.printf(formatter, a[i].getValue() );
		System.out.println();
		for(int i=0; i<a.length; i++)
			System.out.printf(formatter, a[i].getIndex() );
	}
	
	public static void main(String[] args){
		int[] a = {10, 15, 56, 25, 30, 70, 10, 56, 99, 10};
		Element[] array = new Element[10];
		for(int i=0; i<10; i++){
			array[i] = new Element();
			array[i].setIndex(i);
			array[i].setValue(a[i]);
		}
		System.out.println("------Before Create Heap--------");
		print(array);
		System.out.println("------After Create Heap--------");
		CreateHeap(array);
		print(array);
		System.out.println("--------After Heap-------");
		Element[] result = HeapifySort(array);
		print(result);
	}
}