快速排序，c++ 模板技术表述，完全兼容标准库！！！

#pragma once
#include<iterator> // std::iterator_traits
#include<functional> // std::less

#define MYSTD_BEGIN namespace mystd {
#define MYSTD_END }

MYSTD_BEGIN  //名字空间mystd

template<class InputIterator> //输入迭代器
void swap(InputIterator first,InputIterator second)
{
typedef typename std::iterator_traits<InputIterator>::value_type value_type;
value_type temp_val = *first;
*first = *second;
*second = temp_val;
}

//随机访问迭代器
template<class random_access_iterator,class CMP>
void quick_sort(random_access_iterator first,random_access_iterator last,CMP compare)
{
typedef typename std::iterator_traits<random_access_iterator>::value_type value_type;
int n = last - first;
if( n == 0 || n == 1) return ;
if(n == 2)
{
if(compare(*first,*(first + 1))) return ;
mystd::swap(first,first + 1);
return ;
}
random_access_iterator middle = first + (n - 1) / 2;
if(!compare(*first,*middle)) mystd::swap(first,middle);
if(!compare(*first,*(last - 1))) mystd::swap(first,last - 1);
if(!compare(*middle,*(last - 1))) mystd::swap(middle,last - 1);
mystd::swap(middle,last - 1);
value_type middle_val = *(last - 1);
random_access_iterator first_1 = first;
random_access_iterator last_1 = last;
first_1++;
last_1 -= 2;

while(first_1 < last_1)
{
if(!compare(*first_1,middle_val) && !compare(middle_val,*last_1))
{
mystd::swap(first_1++,last_1--);
continue;
}
if(compare(*first_1,middle_val))
{
++first_1;
continue;
}
if(compare(middle_val,*last_1))
{
--last_1;
continue;
}
}
mystd::swap(first_1,last - 1);
quick_sort(first,first_1,compare); // 递归调用
quick_sort(first_1 + 1,last,compare); // 递归调用
}

template<class random_access_iterator>
void quick_sort(random_access_iterator first,random_access_iterator last)
{  //默认升序排列
typedef typename std::iterator_traits<random_access_iterator>::value_type value_type;
quick_sort(first,last,std::less<value_type>()); //转调
}

MYSTD_END // 名字空间mystd

#include<iostream>
#include"test.h"
#include<functional> // std::less,std::greater
#include<cstdlib>  // rand()
#include<vector>

using std::cout;
using std::endl;

int main()
{
const int mn = 100;
std::vector<int> my;
for(int i = 0; i < mn; ++i)
my.push_back(rand() % 10000);  //随机数赋值

cout<<"没有排序的情况"<<endl;
for(int i = 0; i < mn; ++i)
cout<<my[i]<<"\t";
cout<<endl;

cout<<"升序排列的情况"<<endl;
mystd::quick_sort(my.begin(),my.end()); // 升序
for(int i = 0; i < mn; ++i)
cout<<my[i]<<"\t";
cout<<endl;

cout<<"降序排列的情况"<<endl;
mystd::quick_sort(my.begin(),my.end(),std::greater<int>()); //降序
for(int i = 0; i < mn; ++i)
cout<<my[i]<<"\t";
cout<<endl;

system("pause");
return 0;
}