Map

• Map is a Data Structure which stores Key-value pair.
• Map is a container
• No two mapped values can have the same key values.
• Ordered Maps use Red Black Trees.
• Maps are not continuous Example it++ is allowed while it+1 is not.
• All keys are unique if redeclaration happens the pair with that pre-existing key updates.

Implementation

• Maps are implemented using Red-Black trees
• A red-black tree is a kind of self-balancing binary search tree where each node has an extra bit, and that bit is often interpreted as the color (red or black).
• To read in depth about the Red-Black Tree : https://www.geeksforgeeks.org/red-black-tree-set-1-introduction-2/

Functions

• Maps contains many function but mainly begin(),end(),size(),empty(),find(),erase(),clear()
• begin() : Returns an iterator to the first element in the map.
• end() : Returns an iterator to the theoretical element that follows the last element in the map.
• size() : Returns the number of elements in the map.

• empty() : Returns whether the map is empty.
• erase(const g) : Removes the key-value ‘g’ from the map.