Vector Vs Map Stl

Vector Vs Map Stl -

The elements need to implement at least operator<.A multimap guarantees that its elements are stable in memory;

Bjarne stroustrup and herb sutter have both.It always keeps the inserted pairs in sorted order based on the key.The vector is an index to every 25th key which is reset at every insertion and removal (from the closest previous key in the map onwards).

Internally it maintains a balanced binary search tree to store keys.A multimap exposes std::pair as its value type, which requires copying the k (1 for the key in map, one for the value in vector ).

The price is said to be o (n).The vector is an index to every 25th key which is reset at every insertion and removal (from the closest previous key in the map onwards).Hashmap uses a hash, so elements are unsorted, insert/delete is o (1).

To access the 25th*x value, you would get the corresponding key in the index and find it in the map, and then iterate.The map contains the actual sorted values.

Auto entries = std::map{};Template , class allocator = allocator > >.Map of vectors can be very efficient in designing complex data structures.