//program 19.4.2.1.cpp  multiset的用法
#include <iostream>
#include <set>  //使用multiset须包含此文件
using namespace std;
template <class T>
void Print(T first, T last)
{for(;first != last ; ++first)cout << * first << " ";cout << endl;
}
class A
{private:    int n;public:A(int n_ ) { n = n_; }friend bool operator< ( const A & a1, const A & a2 ) {    return a1.n < a2.n; }friend ostream &  operator<< ( ostream & o, const A & a2 ){    o << a2.n;    return o; }friend class MyLess;
};
class MyLess
{
public:bool operator()( const A & a1, const A & a2) //按个位数比大小{ return ( a1.n % 10 ) < (a2.n % 10);  }
};
typedef multiset<A> MSET1;             //MSET1用 "<"比较大小
typedef multiset<A,MyLess> MSET2;     //MSET2用 MyLess::operator()比较大小
int main()
{const int SIZE = 6;A a[SIZE] = { 4,22,19,8,33,40 };MSET1 m1;       m1.insert(a,a+SIZE);   m1.insert(22);cout << "1) " << m1.count(22) << endl; //输出1) 2cout << "2) "; Print(m1.begin(),m1.end()); //输出 2) 4 8 19 22 22 33 40MSET1::iterator pp =  m1.find(19);if( pp != m1.end() ) //条件为真说明找到cout << "found" << endl; //本行会被执行，输出 foundcout << "3) "; cout << * m1.lower_bound(22) << "," <<* m1.upper_bound(22)<< endl;  //输出 3) 22,33pp = m1.erase(m1.lower_bound(22),m1.upper_bound(22));//pp指向被删元素的下一个元素cout << "4) "; Print(m1.begin(),m1.end()); //输出 4) 4 8 19 33 40cout << "5) "; cout << * pp << endl;       //输出 5) 33MSET2 m2; // m2里的元素按n的个位数从小到大排m2.insert(a,a+SIZE);cout << "6) "; Print(m2.begin(),m2.end()); //输出 6) 40 22 33 4 8 19return 0;
}

//program 19.4.3.1.cpp  set的用法：
#include <iostream>
#include <set>  //使用set须包含此文件
using namespace std;
int main()
{typedef set<int>::iterator IT;int a[5] = { 3,4,6,1,2 };set<int> st(a,a+5);    // st里是 1 2 3 4 6pair< IT,bool> result;result = st.insert(5); // st变成  1 2 3 4 5 6if( result.second )    //插入成功则输出被插入元素cout << * result.first  << " inserted" << endl; //输出: 5 insertedif( st.insert(5).second ) cout << * result.first  << endl;elsecout << * result.first << " already exists" << endl; //输出 5 already existspair<IT,IT> bounds = st.equal_range(4);cout << * bounds.first << "," << * bounds.second ; //输出：4,5return 0;
}