I have a std::multimap where key is a custom class. Something like this: Class X { public: std::string s; int x; operator <(const X& other) const { return s < other.s; } }; std::multimap<X, int> mymap; Now, I'd like to use upper_bound and lower_bound to iterate over all elements with the same value of "s". Do I need to imp...
Multimap essentially has groups of data sorted by the key. I want a method by which I could access these individual groups and get their aggregate values. For example, in a std::multimap< string, int > I store {"Group1", 1}, {"Group1", 2}, {"Group1", 3}, {"Group2", 10}, {"Group2", 11}, {"Group2", 12} Having stored these values, ...
I need an equivalent to c++'s std::multimap<K, V, Comp, Alloc> in C-sharp. Does it exist in the standard library? ...
Can I continue to use an multimap iterator even after a call to multimap::erase()? For example: Blah::iterator iter; for ( iter = mm.begin(); iter != mm.end(); iter ++ ) { if ( iter->second == something ) { mm.erase( iter ); } } Should this be expected to run correctly, or is the iterator invalidated f...
Hi all, I'm looking for a C++ container class, that's a lot like a multimap, but slightly different. The container would store pairs of strings. But when I retrieve items from the container using key K, I want to find all the items where K begins with the item's own key. E.G. If I use key "abcde" I want to find items with key "adc" ...
I need a collection that stores entries as key-value pairs (so I can look up values by a key), but I need one that allows multiple values to share the same key using hibernate ...
I'm having difficulty in using std::for_each and other algorithms with a multimap, and want to know if someone could help me developing a functor that could pass the appropriate parameter to the "generic" functions. My specific problem with map/multimap is that their iterators evaluate to a std::pair instead of the contained value (I me...
Java's priority queue is a data structure with O(log n) complexity for put (insertion) and O(log n) for poll (retrieval and removal of the min element). C++ STL's multimap has the same functionality but O(1) complexity for retrieval and removal of the min element (begin and erase). Is there an equivalent in Java ? ...
Hello all, I have std::list<multimap<std::string,std::string>::iterator> > Now i have new element: multimap<std::string,std::string>::value_type aNewMmapValue("foo1","test") I want to avoid the need to set temp multimap and do insert to the new element just to get its iterator back so i could to push it back to the: std::list<m...
Is there an equivalent to the nice MapMaker for MultiMaps? currently i create the cache like this: public static Map<Session,List<Person>> personCache = new MapMaker().weakKeys().makeMap(); the whole point of MultiMap is to avoid the nested List Values. is there any way to construct the multimap with weak keys? ...
This is a composed concurrent list multimap implementation. A lower-level implementation would be better, but more complex. Ignoring the O(n) removal in the sublist, is this the correct way to compose a ConcurrentMap and CopyOnWriteArrayList into a functional ConcurrentMultimap? Are there any unresolved data races? private final Concur...
Instead of implementing my own I was wondering if anyone knows of a histogram or bag datastructure implementation in Objective-C that I can use. Essentially a histogram is a hashmap of lists where the lists contain values that relate to their hash entry. A good example is a histogram of supermarket items where you place each group of it...
Is it possible to have multiple values for the same key in a hash table? If not, can you suggest any such class or interface which could be used? ...
is it possible to have multiple values for a single key in the java dictionary class?? ...
I want to have Map with duplicate keys, I know there are many Map implementations(eclipse shows me about 50), so I bet there must be one that allows this. I know its easy to write your own Map that does this, but i would rather use some existing solution. Maybe something in commons-collections or google-collections? ...
This program stores pairs in a map, counting the number of times a word occurs. The goal is to have the data sorted by number of occurences and output in value/string form. Obviously the normal map sorts by the string key, so I had to reverse it. To do this I read in words, and increment their values appropriately in a map. Then I cre...
I have some data which come with a integer index. I am continuous generating new data which needs to added to the collection of data I have, sorted by that index, at the same time I want to easily be able to go the start of the data and iterate through it. This sounds like std::multimap is just what I need. However, I also need data w...
I have a STL::multimap and I search it with equal_range to return an upper and lower bound. Can I find the number of elements in this range without iterating through them all and counting them one by one? #include <iostream> #include <map> using namespace std; int main () { multimap<int,int> mm; pair<multimap<int, int>::iterat...
I'm doing some heavy processing (building inverse indices) using ints/ longs in Java. I've determined that (un)boxing of standard java.collections maps takes a big portion of the total processing time. (as compared to a similiar implementation using arrays, which I can't use due to memory constraints). I'm looking for a fast 3rd-part...
I have a STL::multimap and I search to populate a std::list with value which key is duplicated. Can I find/insert to a std::list the value of elements for all key where count > 1 without counting them one by one? std::multimap<int, std::string> mm ; mm[0] = "a" ; mm[1] = "b" ; mm[0] = "c" ; mm[2] = "j" ; mm[2] = "k" ; std::list<std...