Summary of C + + technical Issues-7th: map, vector, list, deque each use occasion

Maps are associative, andvectors,lists,anddeque are sequential in type.

Map: Underlying mechanism rb-tree(red-black tree), automatic ordering of elements, key-value pairs.

Vector: operates in a similar way to array, with dynamic space growth. is a continuous space that supports random access.

Advantages:

? Memory is dynamically growing and does not require a specified memory size.

? Support for random access, i.e. support [] and vector.at ().

Disadvantages:

? Internal Insert delete operation is inefficient.

? push and popare only available at the end of the vector .

List: The use of space is absolutely accurate, not a waste of it. Deleting inserts is simple, but does not support random access. Bidirectional linear list.

Advantages:

? Easy to insert and remove.

? Can be push,popon both ends.

Cons: cannot be accessed randomly.

Deque: Continuity space for bidirectional openings. The insertion and deletion of elements are made at each end of the tail.

Advantages:

? Random access.

? Easy to insert and remove.

? Can be push,popon both ends.

Cons: Internal implementation is complex and less efficient. Sort, etc. not applicable.

Summary of Use occasions:

? Requires efficient access, not in terms of insertion and deletion efficiency, using vectors.

? It takes a lot of insertions and deletions, doesn't care about access, uses list.

? Care access, and both ends of the data are inserted and deleted, using deque.

? Key-value pairs, one-to-one mapping, using map.

Summary of C + + technical Issues-7th: map, vector, list, deque each use occasion