CODEWITHSUNDEEP
c++unordered-map
glarkou
glarkou

Reputation: 7101

Unordered_map with vector usage

I have an unordered_map:

std::tr1::unordered_map<unsigned int, vector<unsigned int> > duplicates;

Anad I would like to insert:

duplicates.insert(make_pair(1, 2));
duplicates.insert(make_pair(1, 5));
duplicates.insert(make_pair(1, 6));

into the vector because they share the same key. I use a for loop for inserting pairs. How can I initialise the vector if no items share the same key and it is the first time that I find that key without searching the whole unordered_map?

I do not want to first use find (to get the vector if exist) and then insert. Is that possible?

Upvotes: 0

Views: 1822

Answers (1)

Jorge Israel Pe&#241;a
Jorge Israel Pe&#241;a

Reputation: 38576

Sorry if I misunderstood your question, but perhaps you might find use in something like unordered_multimap?

Unordered multimaps are associative containers that store elements formed by the combination of a key value and a mapped value, much like unordered_map containers, but allowing different elements to have equivalent keys.

Upvotes: 1

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