compare two multimaps c++

Question

I have two multimaps.i would like to create a new multimap which has the common key-value pairs in the given those two multimaps:

for eg:

#include &l         


        

Answer 1

Use the std::set_intersection function template from

std::multimap newMap;
std::set_intersection(map1.begin(), map1.end(), 
                      map2.begin(), map2.end(), 
                      std::inserter(newMap, newMap.begin());

Edit Yeah, apparently this doesn't work for a multimap as it would for a map. I suggest the following:

std::multimap newMap;
std::vector::value_type> v1(map1.begin(), map1.end());
std::sort(v1.begin(), v1.end());
std::vector::value_type> v2(map2.begin(), map2.end());
std::sort(v2.begin(), v2.end());
std::set_intersection(v1.begin(), v1.end(), 
                      v2.begin(), v2.end(), 
                      std::inserter(newMap, newMap.begin());