multimap can return the number of pairs with the same key : multimap « map multimap « C++ Tutorial

1. C++ Tutorial
2. map multimap
3. multimap

#include <map>
#include <iostream>

using namespace std;

typedef map <int, string> MAP_INT_STRING;
typedef multimap <int, string> MMAP_INT_STRING;

int main ()
{
    MMAP_INT_STRING mmapIntToString;

    mmapIntToString.insert (MMAP_INT_STRING::value_type (3, "Three"));
    mmapIntToString.insert (MMAP_INT_STRING::value_type (45, "Forty Five"));

    cout << "The number of pairs in the multimap with 1000 as their key: "
        << mmapIntToString.count (1000) << endl;

    return 0;
}