STL中的nth_element()方法的使用

#pragma warning(disable: 4786)

#include <iostream>

#include <algorithm>

#include <vector>

using namespace std;

int main()

{

const int VECTOR_SIZE = 50 ;

vector<int> Numbers(VECTOR_SIZE) ;

vector<int>::iterator start, end, it ;

// Initialize vector Numbers

for(int i=0;i<50;++i){

Numbers[i]=i;

}

//由于赋值时是有序的，下面random_shuffle()方法将这些数据的顺序打乱

random_shuffle(Numbers.begin(),Numbers.end());

start = Numbers.begin() ;

end = Numbers.end() ;

cout << "Before calling nth_element/n" << endl ;

cout << "Numbers { " ;

for(it = start; it != end; it++)

cout << *it << " " ;

cout << " }/n" << endl ;

//排序
nth_element(start, start+8, end) ;

cout << "After calling nth_element/n" << endl ;

cout << "Numbers { " ;

for(it = start; it != end; it++)

cout << *it << " " ;

cout << " }/n" << endl ;

system("pause");

}

#include "stdafx.h"
#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

int _tmain(int argc, _TCHAR* argv[])
{
vector<int> a;
for(int i = 0; i < 50; i++)
{
a.push_back(i);
}

std::random_shuffle(a.begin(),a.end());//函数说明见下

for(int j = 0; j < 50; j++)
{
cout<<a[j]<<" ";
}
cout<<endl;

std::nth_element(a.begin(),a.begin()+8,a.end());

for(int k = 0; k < 50; k++)
{
cout<<a[k]<<" ";
}
cout<<endl;

system("pause");
return 0;
}

template<class RandomAccessIterator>
void random_shuffle(
RandomAccessIterator _First, //指向序列首元素的迭代器
RandomAccessIterator _Last  //指向序列最后一个元素的下一个位置的迭代器
);