快速排序

 1 #include "stdafx.h"
 2 #include <iostream>
 3 #include<stack>
 4 #include<exception>
 5 using namespace std;
 6 
 7 
 8 void swap(int* a ,int *b)
 9 {
10     int temp = *a;
11     *a=*b;
12     *b=temp;
13 }
14 int Partition(int data[],int length,int start,int end)
15 {
16     if(data==NULL||length<=0||start<0||end>=length)
17         throw new std::exception("Invalid Parameters");
18     int index = start;
19     swap(&data[index],&data[end]);
20     int small = start-1;//small用来记录比枢轴小的数的位置.
21     for(index=start;index<end;++index)
22     {
23         if(data[index]<data[end])
24         {
25             ++small;//找到一个比枢轴小的数就+1,
26             if(small!=index)
27                 swap(&data[index],&data[small]);
28         }
29     }
30     ++small;
31     swap(&data[small],&data[end]);
32     return small;
33 }
34 void QuickSort(int data[],int length,int start,int end)
35 {
36     if(start==end)
37         return;
38     int index = Partition(data,length,start,end);
39     if(index>start)
40     QuickSort(data,length,start,index-1);
41     if(index<end)
42     QuickSort(data,length,index+1,end);
43 }
44 const int num = 6;
45 int _tmain(int argc, _TCHAR* argv[])
46 {
47     int data[num]={4,3,1,6,10,2};
48     QuickSort(data,num,0,num-1);
49 
50     cout<<"最后结果:"<<endl;
51     for(int i = 0;i!=num-1;++i)
52     cout<<data[i]<<"->";
53     cout<<data[num-1]<<endl;
54     return 0;
55 }