C++ std::map: Key-Value Pairs Explained

In C++, std::map is an associative container used to store key-value pairs. It provides a fast way to look up and access the value associated with a key, functioning similarly to a dictionary or hash table. Elements in std::map are sorted in the order of their keys, and each key can only appear once in the container.

The std::map data structure is typically used for quickly looking up the value corresponding to a specific key, such as implementing dictionaries, counters, or indexes. Its internal implementation is based on a red-black tree, so on average, the time complexity for lookups, insertions, and deletions is O(log n).