chapter9-26.cpp

STL程序员开发指南源码

//文件名:CHAPTER9-26.cpp
#include <set>
#include <iostream>
#if _MSC_VER > 1020   // if VC++ version is > 4.2
   using namespace std;  // std c++ libs implemented in std
#endif
int main( )
{
   multiset <int> ms1;
   multiset <int> :: const_iterator ms1_AcIter, ms1_RcIter;
   ms1.insert( 10 );
   ms1.insert( 20 );
   ms1.insert( 20 );
   ms1_RcIter = ms1.find( 20 );
   cout << "The first element of multiset ms1 with a key of 20 is: "<< *ms1_RcIter << "." << endl;
   ms1_RcIter = ms1.find( 40 );
   // 如果不存在, 将返回end( ) 
   if ( ms1_RcIter == ms1.end( ) )
      cout << "The multiset ms1 doesn't have an element "<< "with a key of 40." << endl;
   else
      cout << "The element of multiset ms1 with a key of 40 is: "<< *ms1_RcIter << "." << endl;
   ms1_AcIter = ms1.end( );
   ms1_AcIter--;
   ms1_RcIter = ms1.find( *ms1_AcIter );
   cout << "The first element of ms1 with a key matching" << endl
        << "that of the last element is: "<< *ms1_RcIter << "." << endl;
   //返回第一个元素的迭代器
   if ( ms1_RcIter == --ms1.end( ) ) cout << "This is the last element of multiset ms1." << endl;
   else cout << "This is not the last element of multiset ms1." << endl;
}