分治法－－快速排序

 

package divideConquer;import java.util.Arrays;/* * QuickSort Complexity is nlog(n) * 1.select one of a number as benchmark,then find the benchmark's absolute position * 2.with the benchmark seperate array to two part * 3.use the way like 1 *  * */public class QuickSort {public static int partion(int data[],int low,int high){int i=low,j=high-1;while(i<j){while(data[j]>=data[i]&&i<j)j--;if(i<j) {swap(data,i++,j);}while(data[i]<=data[j]&&i<j)i++;if(i<j) {swap(data,i,j--);}}return i;}public static void swap(int data[],int i,int j){int tmp = data[i];data[i] = data[j];data[j] = tmp;}public static void quickSort(int data[],int low,int high){if(low+1>=high)return ;int s = partion(data,low,high);quickSort(data,low,s+1);quickSort(data,s+1,high);}public static void main(String args[]){int data[] = {9,5,1,2,6,3,4,3};quickSort(data,0,data.length);System.out.println(Arrays.toString(data));}}