programming.txt

Concepts
    **Type erasure** is the process in which the compiler replaces the generic types with their bound or object.
    **Plain old java object (POJO)** is a simple java object that does not require any fancy library in classpath other than the JVM to be instantiated.

SOLID
    Single responsibility principle
        A class should have only a single responsibility (i.e. changes to only one part of the software's specification should be able to affect the specification of the class).
    Open/closed principle
        Software entities should be open for extension, but closed for modification.
    Liskov substitution principle
        Objects in a program should be replaceable with instances of their subtypes without altering the correctness of that program.
    Interface segregation principle
        Many client-specific interfaces are better than one general-purpose interface.
    Dependency inversion principle
        One should depend upon abstractions, concretions.


Given a balanced BST
    *       4
   2      5
 1   3*
    Depth First Traversals
        Inorder (Left, Root, Right) : 1 2 3 4 5
        Preorder (Root, Left, Right) : 4 2 1 5 3
        Postorder (Left, Right, Root) : 1 3 2 5 4
    Breadth First 4 2 5 1 3


Sorting algorithms
    Bubble sort. Time O(N^2) Space O(1)
    Selection sort. Time O(N^2) Space O(1)
    Merge sort. Time O(N log(N) Space O(1)
    Quick sort. Time average O(N log(N). Worst case O(N^2). Space O(log(N)).