java 实现 插入排序 希尔排序 冒泡排序 快速排序 堆排序 归并排序 【完美版】

package net.okren.java;
import java.util.*;
import java.io.*;

public class SortTest{
	
	//插入排序;
	public static void insertionSort(Comparable[] data){
		System.out.println("insertSort() ...");
		int j;
		for(int p = 1; p < data.length; p++){
			Comparable temp = data[p];
			for(j = p; j > 0 && temp.compareTo(data[j - 1]) < 0; j--){
				data[j] = data[j - 1];
			}
			
			data[j] = temp;
		}	
	}
	
	
	//希尔排序;
	public static void shellSort(Comparable[] data){
		System.out.println("shellSort() ...");
		int j;
		for(int gap = data.length / 2; gap > 0; gap /= 2){
			
			for(int i = gap; i < data.length; i++){
				Comparable temp = data[i];
				for(j = i; j >= gap && temp.compareTo(data[j - gap]) < 0; j -= gap){
					data[j] = data[j - gap];
				}
				data[j] = temp;
			}
		}		
	}
	
	
	//堆排序；
	public static void heapSort(Comparable[] data){
		System.out.println("heapSort() ...");
			//buildHeap,
		for(int i = data.length / 2; i >= 0; i--){
			shiftDown(data, i, data.length);
			
		}
		
		//deleteMax,
		for(int i = data.length - 1; i > 0; i--){
			swap(data, 0, i);
			shiftDown(data, 0, i);
		}
	
	}
	
	private static void shiftDown(Comparable[] data, int i, int n){
		int child;
		Comparable temp;
		for(temp = data[i]; leftChild(i) < n; i = child){
			child = leftChild(i);
			if(child != n - 1 && data[child].compareTo(data[child + 1]) < 0){
				child++;
			}
			if(temp.compareTo(data[child]) < 0){
				data[i] = data[child];
			}else{
				break;
			}
		}
		data[i] = temp;
	}
	
	private static int leftChild(int i){
		return 2 * i + 1;
	}
	
	
	
	
	
	
	//冒泡排序
	public static void bubbleSort(Comparable[] data){
		System.out.println("bubbleSort() ...");
		for(int i = data.length - 1; i > 0; i--){
			boolean isChanged = false;
			for(int j = 0; j < i; j++){
				if(data[j].compareTo(data[j + 1]) > 0){
					Comparable temp = data[j];
					data[j] = data[j + 1];
					data[j + 1] = temp;
					isChanged = true;
				}
				
			}
			if(!isChanged) break;
		}
		
	}
	
	//快速排序；
	
	
	public static void quickSort(Comparable[] data){
		System.out.println("quickSort() ...");
		
		quickSort(data, 0, data.length - 1);		
	}
	
	private static void quickSort(Comparable[] data, int left, int right){
		if(left + 10 <= right){
			Comparable pivot = middle3(data, left, right);//执行三数中值分割法，
			int i = left, j = right - 1;
			for(;;){
				while(data[++i].compareTo(pivot) < 0){}
				while(data[--j].compareTo(pivot) > 0){}
				if(i < j){
					swap(data, i, j);
				}else{
					break;
				}
			}
			
			swap(data, i, right - 1);
			quickSort(data, left, i -1);
			quickSort(data, i + 1, right);
			
		}else{
			System.out.println("insertionSort() ...");
			insertionSort(data);
		}
	}
	
	private static Comparable middle3(Comparable[] data, int left, int right){
		int center = (left + right) / 2;
		if(data[center].compareTo(data[left]) < 0){
			swap(data, left, center);
		}
		if(data[right].compareTo(data[left]) < 0){
			swap(data, left, right);
		}
		if(data[right].compareTo(data[center]) < 0){
			swap(data, center, right);
		}
		swap(data, center, right - 1);
		return data[right - 1];
	}
	
	private static void swap(Comparable[] data, int i, int j){
		Comparable temp = data[i];
		data[i] = data[j];
		data[j] = temp;
	}
	
	//归并排序；
	
	public static void mergeSort(Comparable[] data){
		System.out.println("mergeSort() ...");
		 Comparable[] tempData = new Comparable[data.length];
		 mergeSort(data, tempData, 0, data.length - 1);
		
		
	}
	
	
	private static void mergeSort(Comparable[] data, Comparable[] tempData, int left, int right){
		
		if(left < right){
			int center = (left + right) / 2;
		  mergeSort(data, tempData, left, center);
		  mergeSort(data, tempData, center + 1, right);
		  merge(data,tempData, left, center + 1, right);
		}
	}
	
	private static void merge(Comparable[] data, Comparable[] tempData, int leftPos, int rightPos, int rightEnd){
		int leftEnd = rightPos - 1;
		int tempPos = leftPos;
		int num = rightEnd - leftPos + 1;
		
		while(leftPos <= leftEnd && rightPos <= rightEnd){
			if(data[leftPos].compareTo(data[rightPos]) <= 0){
				tempData[tempPos++] = data[leftPos++];
			}else{
				tempData[tempPos++] = data[rightPos++];
				
			}
		}
		
		while(leftPos <= leftEnd){
			tempData[tempPos++] = data[leftPos++];
		}
		
		while(rightPos <= rightEnd){
			tempData[tempPos++] = data[rightPos++];
		}
		
		for(int i = 0; i < num; i++, rightEnd--){
			data[rightEnd] = tempData[rightEnd];
		}
	}
	
	
	// 构建初始数据
	public static Comparable[] getData(int num){
		Comparable[] data = new Comparable[num];
		Random r = new Random();
		for(int i = 0; i < data.length; i++){
			data[i] = r.nextInt(num);
		}
		
		return data;
	}
	
	//从键盘输入 构建初始数据；
	public static Comparable[] getInputData(){
		
		
		System.out.println("eg.: 3,6,1,2,7,2,6, ...");
		try{
			
			 BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
		   String line = in.readLine();
		   StringTokenizer st = new StringTokenizer(line, ",");
		   Comparable[] data = new Comparable[st.countTokens()];
		   int i = 0;
		   while(st.hasMoreTokens()){
			   data[i++] = Integer.parseInt(st.nextToken());
		   }
		 
		   return data;
			
		
	}catch(IOException e){
		e.printStackTrace();
		return null;
	}
		
	}
	
	
	public static void main(String[] args){
		
		//Comparable[] data = getData(20);
		Comparable[] data = getInputData();
		//排序前输出
		for(int i = 0; i < data.length; i++){
			System.out.print(data[i] + ", ");
		}
		System.out.println();
		//排序
		//insertionSort(data);
		//shellSort(data);
		//bubbleSort(data);
		//mergeSort(data);
		//quickSort(data);
		heapSort(data);
		//排序后输出
		for(int i = 0; i < data.length; i++){
			System.out.print(data[i] + ", ");
		}
		System.out.println();
		
	}
}

评论

1 楼 bo_hai 2011-02-17  

找到了我想要学习的知识点。有java实现算法和用C实现是有所不同的。