Java利用Strategy模式实现堆排序

策略设计模式（Strategy）：可以整体的替换一个算法的实现部分，能够整体的替换算法，能让我们轻松地用不同方法解决同一个问题。本文将利用Strategy模式实现堆排序，感兴趣的可以学习一下

1、图示

2、项目资产

3、源代码

接口类：HeapSortHandle

public interface HeapSorterHandle { public void swap(int index); public int length(); public void setArray(Object array); public void adjustHeap(int i, int length); }

接口派生类： DoubleHeapSorter

public class DoubleHeapSorter implements HeapSorterHandle{ private double[] array = null; public void swap(int index) { double temp = array[index]; array[index] = array[0]; array[0] = temp; } public int length() { return array.length; } public void setArray(Object array) { this.array = (double[])array; } public void adjustHeap(int i, int length) { double temp = array[i]; for(int k=i*2+1;ktemp) { array[i] = array[k]; i = k; } else { break; } } array[i] = temp; } }

具体算法类 HeapSorter ：

public class HeapSorter { private int length = 0; private HeapSorterHandle itsSortHandle = null; public HeapSorter(HeapSorterHandle handle) { itsSortHandle = handle; } public void Sort(Object array) { itsSortHandle.setArray(array); length = itsSortHandle.length(); if (length <= 1) return; for(int i=length/2-1;i>=0;i--) { itsSortHandle.adjustHeap(i,length); } for(int j=length-1;j>0;j--) { itsSortHandle.swap(j); itsSortHandle.adjustHeap(0,j); } return; } }

主类Main：

import java.util.Arrays; public class Main { public static void main(String[] args) { HeapSorter HS = new HeapSorter(new DoubleHeapSorter()); double []array = {1,5,2,3,4,6,7}; System.out.println("堆排序前:"+Arrays.toString(array)); HS.Sort(array); System.out.println("堆排序后:"+Arrays.toString(array)); } }

输出：