chapter10-26.cpp

C++STL程序员开发指南

//文件名:CHAPTER10-26.cpp
#include <map>
#include <iostream>
#if _MSC_VER > 1020   // if VC++ version is > 4.2
   using namespace std;  // std c++ libs implemented in std
#endif
int main( )
{
   multimap <int, int> m1;
   int i;
   typedef pair <int, int> Int_Pair;
   m1.insert ( Int_Pair ( 1, 1 ) );
   m1.insert ( Int_Pair ( 2, 1 ) );
   m1.insert ( Int_Pair ( 1, 4 ) );
   m1.insert ( Int_Pair ( 2, 1 ) );
   // Elements do not need to have unique keys in multimap, so duplicates are allowed and counted
   i = m1.count( 1 );
   cout << "The number of elements in m1 with a sort key of 1 is: "<< i << "." << endl;
   i = m1.count( 2 );
   cout << "The number of elements in m1 with a sort key of 2 is: "<< i << "." << endl;
   i = m1.count( 3 );
   cout << "The number of elements in m1 with a sort key of 3 is: "<< i << "." << endl;
}