C++ Multimap Explained: Usage Guide

In C++, multimap is an associative container similar to map, but it allows keys in key-value pairs to be repeated. This means that multimap can contain multiple elements with the same key, so the elements in multimap are stored in order of their keys.

The usage of multimap is similar to that of map, where you can add key-value pairs using the insert() method, search for specific keys’ elements using the find() method, delete elements using the erase() method, and traverse the multimap using iterators. Multimap also offers specific operations for multiple keys, such as the equal_range() method which returns the elements matching a given key, and the count() method which returns the number of elements for a specific key.

In general, multimap is a very useful data structure, especially suitable for situations where multiple elements with the same key need to be stored.