std::sort 排序使用方法

// 
//alg_std::sort.cpp
//
#include <vector>
#include <algorithm>
#include <functional>      // For greater<int>( )
#include <iostream>
using namespace std;

// Return whether first element is greater than the second
bool UDgreater ( int elem1, int elem2 )
{
	return elem1 > elem2;
}

class Csort
{
public:

// Return whether first element is less than the second
	bool operator () (int a,int b) const
	{
		return a<b;
	};
};

int main( )
{
	vector <int> v1;
	vector <int>::iterator Iter1;
	int arr[12];
	int i;
	for ( i = 0 ; i <= 5 ; i++ )
	{
		v1.push_back( 2 * i );
		arr[i]=2*i;
	}
	for ( i = 6 ; i <= 11 ; i++ )
	{
		arr[i]=23-2*i;
	}

	int ii;
	for ( ii = 0 ; ii <= 5 ; ii++ )
	{
		v1.push_back( 2 * ii + 1 );
	}

	cout << "Original vector v1 = ( " ;
	for ( Iter1 = v1.begin( ) ; Iter1 != v1.end( ) ; Iter1++ )
		cout << *Iter1 << " ";
	cout << ")" << endl;
	cout << "Original array arr = ( " ;
	for ( int n=0;n<12;n++ )
		cout << arr
 << " ";
	cout << ")" << endl;

	//std::sort 默认排序方式
	sort( v1.begin( ), v1.end( ) );
	cout << "Sorted vector v1 = ( " ;
	for ( Iter1 = v1.begin( ) ; Iter1 != v1.end( ) ; Iter1++ )
		cout << *Iter1 << " ";
	cout << ")" << endl;

	//使用自定义函数给数组排序，第三个参数为函数指针UDgreater
	//第二个参数为数据最大地址的后一位指针&arr[12]；
	sort( &arr[0], &arr[12],UDgreater);

	cout << "Resorted (UDgreater) array arr = ( " ;
	for ( int n=0;n<12;n++ ) cout << arr
 << " ";
	cout << ")" << endl;
	//使用自定义类的 重载operator() 函数给数组排序，第三个参数为【类名()】
	sort( &arr[0], &arr[12],Csort());

	cout << "Resorted (Csort()) arr = ( " ;
	for ( int n=0;n<12;n++ ) cout << arr
 << " ";
	cout << ")" << endl;

	//使用<functional>库中 greater<int>( ) 给向量V1排序；
	sort( v1.begin( ), v1.end( ), greater<int>( ) );
	//sort( v1.begin( ), v1.end( ), Csort() );

	cout << "Resorted (greater) vector v1 = ( " ;
	for ( Iter1 = v1.begin( ) ; Iter1 != v1.end( ) ; Iter1++ )
		cout << *Iter1 << " ";
	cout << ")" << endl;

	// A user-defined (UD) binary predicate can also be used
	//sort( v1.begin( ), v1.end( ), UDgreater );
	sort( v1.begin( ), v1.end( ),Csort());
	cout << "Resorted (UDgreater) vector v1 = ( " ;
	for ( Iter1 = v1.begin( ) ; Iter1 != v1.end( ) ; Iter1++ )
		cout << *Iter1 << " ";
	cout << ")" << endl;

	getchar();
	return 0;
}