3.排序--快速排序
2012-09-13 17:12 jiutianhe 阅读(350) 评论(0) 编辑 收藏 举报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 stub ArrayList<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 } } }