# Algorithm Arsenal
- sort
  - merge sort n log n
  - insertion sort
  - heap sort (n log n)
  - bubble sort n log n
- graph search
  - DFS
  - BFS
  - shortest path - Djikstra's algorithm
- binary search (keep halving problem)
- map reduce

# Data Structures Arsenal
- array
- linked lists
- set
  - hash
  - less than - stored as binary trees
- map
  - hash - if there is a collision, insertion can be as worse as O(n)
  - less than - stored as binary trees
- stacks
- queues
- trees
  - binary search tree
  - trie
- graph
!!!! UNDERSTAND HOW THESE STRUCTURES WORK !!!!

# Design questions (for self)
- concurrency
- recursion & induction
- dynamic programming
- scalability & memory limits

# OOP
- inheritance - allows child class to inherit props of parent (minus private)
- abstract
  - can only be extended, not instantiated
  - can have implemented methods and abstract methods
- polymorphism - allows subclass to act like superclass
  - overriding - runtime
  - overloading - compile time
- encapsulation - hide methods and attributes inside class (black box)
- templates (done at compile time)