排序算法（二）
package sort;import java.util.Random;public class QuickSort {private int[] input;private int partition(int[] input,int p,int r){int x = input[r];int i = p -1;for(int j = p; j< r;j++){if(input[j] <= x){i++;int temp = input[i];input[i] = input[j];input[j] = temp;}}int temp = input[i+1];input[i+1] = input[r];input[r] = temp;return i + 1;}public void out(){for(int i = 0;i< input.length; i++){System.out.print(input[i] + " ");}System.out.println();}public QuickSort(int[] input){this.input = input;}public void quickSort(){sort(input,0,input.length -1 );}private void sort(int[] input,int p,int r){if(p<r){int q = partition(input, p, r);sort(input, p, q-1);sort(input, q+1, r);}}public int randomPartition(int[] input,int p,int r){int i = random(p, r);int temp = input[i];input[i] = input[r];input[r] = temp;return partition(input, p, r);}public void randomQuickSort(){randomQuickSort(input, 0, input.length -1);}private void randomQuickSort(int[] input,int p,int r){if(p < r){int q = randomPartition(input, p, r);randomQuickSort(input, p, q-1);randomQuickSort(input, q+1, r);}}public static int random(int p,int r){return new Random().nextInt(r + 1 -p) + p;}private int hoarePartition(int input[],int p,int r){int x = input[p];int i = p;int j = r;while(true){while(input[j] > x){j-- ;}while(input[i] < x){i++ ;}if(i < j){int temp = input[i];input[i] = input[j];input[j] = temp;}else{return j;}}}private void hoareSort(int input[],int p,int r){if(p < r){int q = hoarePartition(input, p, r);hoareSort(input, p, q -1);hoareSort(input, q +1, r);}}public void hoareSort(){hoareSort(input, 0, input.length -1);}public static void main(String[] args){int[] input = {2,8,7,1,3,5,6,4};for(int j = 0; j < input.length;j++){System.out.print(input[j] + " ");}System.out.println();QuickSort sort = new QuickSort(input);//sort.quickSort();//sort.randomQuickSort();sort.hoareSort();sort.out();}}