unordered-map
Storing elements in an unordered_set vs storing them in an unordered_map
Suppose I have the following User struct: struct User { string userId; UserType userType; // UserType is just an enumeration[详细]
2023-04-10 16:15 分类:问答Size in bytes of a structure containing unordered_map
Need to find the exact size in bytes, occupied by a tree data structure that I have implemented. Node Structure is as follows[详细]
2023-04-06 21:16 分类:问答boost::unordered_map -- Need to specify a custom hash function for hashing std::set<int>?
I\'d like use boost::unordered_map<key,value>, where key is a std::set<int>. Since a set of integers is no built-in type, I assumed I had to supply my own hash function (or, rather, I was[详细]
2023-04-06 02:50 分类:问答unordered_map::find() inserts the key of the lookup
Is it a feature of unordered_map::find() to insert the key that we lookup with 0 value automatically?[详细]
2023-04-05 16:59 分类:问答iterators in Unordered (or Hash) Maps
As far as I understand, Hashmaps are preferable to standard maps because you can find elements in close to O(1) time. This is done by using a hash or the key as an array lookup. We then resolve any co[详细]
2023-04-01 09:52 分类:问答How to see values in boost:unordered_map in debug mode with vs2010
I have the following code... typedef boost::unordered_map<开发者_如何学JAVAint, boost::unordered_map<int, float>* > User_item_rating_map;[详细]
2023-04-01 02:29 分类:问答unordered_map hash function c++
I need to define an unordered_map like this unordered_map<pair<int, int>, *Foo>, what is the syntax for defining and passing a hash and equal functions to this map?[详细]
2023-03-31 02:42 分类:问答performance of find in an unordered_map
I know this is probably a stupid questi开发者_开发技巧on, but I wanted to make sure and I couldn\'t readily find this information.[详细]
2023-03-27 11:00 分类:问答What bit hash function does unordered_map use?
What bit hash does unordered_map of C++0x use by default? std::hash function 开发者_开发问答returns size_t. Does that mean unordered_map uses a 16 bit hash function?std::unordered_set uses std::hash b[详细]
2023-03-26 15:09 分类:问答ordered version of unordered_map?
In my following program I\'m currently using unordered_map just because I wanted O(1) search/insert time. But now I wanted the items to be ordered. Sorting it every time is very inefficient. What are[详细]
2023-03-25 05:19 分类:问答