Knowledge Base

A lightweight programming knowledge base with examples. Although is Java oriented the most of the concepts are language agnostic.

Short content

1. Java Concurrency
2. Data Structures
3. Design Patterns
4. Sorting Algorithms
5. Java Interview Questions

Java Concurrency

• Locks
  • ReentrantLock demo
  • ReentrantReadWriteLock demo
• Synchronizers
  • Explanations + diagrams
  • CountDownLatch demo
  • CyclicBarrierDemo demo
  • SemaphoreDemo demo
  • ThreadLocalDemo demo
• ForkJoin - some recursive task that are appropriate for ForkJoin computations
  • Tree printer
  • Fibonacci
• Problems - a collection of some common concurrent problems
  • Producer-consumer with Lock
  • Producer-consumer with Blocking Queue
  • Ensure thread sequence with join

Data Structures

See the packages here.

• List - implementations of Java java.util.List interface
  • Array List
    • Test
  • Singly Linked List
    • Test
• Hash Table - implementations of Java java.util.Map and java.util.Set interface.
  • Hash Map
    • Test
  • Hash Set
    • Test
• Tree - implementations Tree data structure.
  • Binary Search Tree
  • Prefix Tree (Trie)

Design patterns

See the packages here.

• Creational patterns
  • Builder
  • Factory Method
  • Singleton
  • Prototype
• Structural patterns
  • Adapter (Wrapper, or Translator)
  • Bridge
  • Composite
  • Decorator
  • Facade
  • Proxy
• Behavioral patterns
  • Command
  • Observer (or Publish/Subscribe)
  • State
  • Strategy
  • Visitor

Sorting Algorithms

See the packages here.

Implementation link	Average case	Worst case	Memory	Stable	Restrictions
Insertion Sort	n^2	n^2	1	yes	no
Binary Insertion Sort	n^2	n^2	1	yes	no
Selection Sort	n^2	n^2	1	no	no
Bubble Sort	n^2	n^2	1	yes	no
Merge Sort	n.log(n)	n.log(n)	n	yes	no
Quick Sort	n.log(n)	n^2	n.log(n)	no	no
Heap Sort	n.log(n)	n.log(n)	1	no	no
Counting Sort	n	n^2	n	yes	integers
Bucket Sort	n	n^2	n	yes	integers
Radix Sort	n	n	n	no	integers