3.排序--快速排序

C语言版本：

/*快速排序  2012.2.25*/#include <stdio.h>int partion(int a[],int low,int high)   //返回枢轴位置{    int i=low;    int j=high;    int pivot=a[low];    while(i<j)    {        while(i<j&&a[j]>=pivot)        {            --j;        }        a[i]=a[j];        while(i<j&&a[i]<=pivot)        {            ++i;        }        a[j]=a[i];    }a[i]=pivot;    return i;}void quickSort(int a[],int low,int high)  //快速排序{    if(low<high)    {        int pivotpos=partion(a,low,high);        quickSort(a,low,pivotpos-1);        quickSort(a,pivotpos+1,high);    }}int main(int argc, char *argv[]){    int n;    while(scanf("%d",&n)!=EOF)    {        int i;        int *a=new int[n];        for(i=0;i<n;i++)        {            scanf("%d",&a[i]);        }        quickSort(a,0,n-1);        for(i=0;i<n;i++)        {            printf("%d ",a[i]);        }        printf("\n");    }    return 0;}

 Java 版本：

package algorithm.sort;import java.io.BufferedReader;import java.io.FileInputStream;import java.io.FileOutputStream;import java.io.IOException;import java.io.InputStreamReader;import java.io.OutputStreamWriter;import java.util.ArrayDeque;import java.util.ArrayList;import java.util.Collections;import java.util.Deque;import java.util.LinkedList;import time.Timing;public class QuickSort{public <T extends Comparable<T>> void quickSort1(ArrayList<T> arr,int l,int u){if (l>=u) {return;}int m=l;for (int i = l+1; i <= u; i++) {if (arr.get(i).compareTo(arr.get(l))<0) {Collections.swap(arr, ++m, i);}}Collections.swap(arr, l, m);quickSort1(arr, l, m-1);quickSort1(arr, m+1, u);}public <T extends Comparable<T>> void quickSort2(ArrayList<T> arr,int l,int u){if (l>=u) {return;}T temp=arr.get(l); int i=l; int j=u;while(i<j){for (; i < j && arr.get(j).compareTo(temp)>=0; j--);for (; i < j && arr.get(i).compareTo(temp)<=0; i++);if (i>j) {break;}Collections.swap(arr, i, j);}Collections.swap(arr, j, l);quickSort2(arr, l, j-1);quickSort2(arr, j+1, u);}public static void main(String[] args) {// TODO Auto-generated method stubArrayList<Integer> arr=new ArrayList<Integer>();QuickSort qs=new QuickSort();try {FileOutputStream fos = new FileOutputStream("D:\\workspace\\DataStructures\\src\\algorithm\\sort\\rank_data.txt");OutputStreamWriter w = new OutputStreamWriter(fos, "UTF-8");InputStreamReader fr = new InputStreamReader(new FileInputStream("D:\\workspace\\DataStructures\\src\\algorithm\\sort\\random_data.txt"));BufferedReader br = new BufferedReader(fr);String line = null;while ((line = br.readLine()) != null) {arr.add(Integer.parseInt(line));}Timing sorTimer = new Timing();double timeInSec;sorTimer.start();qs.quickSort2(arr, 0, arr.size() - 1);timeInSec = sorTimer.stop();for (int i : arr) {w.write(i + "\n");}System.out.println(timeInSec);br.close();fr.close();w.close();fos.close();} catch (IOException e) {// TODO: handle exception}}}