/LeetCode-Solutions-And-Data-Structure-Analysis

A collection of LeetCode novel solutions that is implemented in Java. An overview about data structure for interview questions

Primary LanguageJava

LeetCode Solutions in Java

A collection of LeetCode novel solutions that is implemented in Java. It would support you to solve the problems from easy to hard by the simplest ways.

Solutions LeeCode

# Problem Difficulty Source code Solution
1 Two Sum Medium Java 1. Hash O(n) and O(n) space.
2. Sort and search with two points O(n) and O(1) space.
2 Add Two Numbers Medium Java Take care of the carry from lower digit.
--- To-be-updated soon ---------- ----------- --------

Big O performance

Below are the Big O performance of common functions of different Java Collections.

List Add Remove Get Contains Next Data Structure
ArrayList O(1) O(n) O(1) O(n) O(1) Array
LinkedList O(1) O(1) O(n) O(n) O(1) Linked List
Set Add Remove Contains Next Size Data Structure
HashSet O(1) O(1) O(1) O(h/n) O(1) Hash Table
LinkedHashSet O(1) O(1) O(1) O(1) O(1) Hash Table + Linked List
EnumSet O(1) O(1) O(1) O(1) O(1) Bit Vector
TreeSet O(log n) O(log n) O(log n) O(log n) O(1) Red-black tree
ConcurrentSkipListSet O(log n) O(log n) O(log n) O(1) O(n) Skip List
  • Note: h is the table capacity
Queue Offer Peak Poll Remove Size Data Structure
PriorityQueue O(log n) O(1) O(log n) O(n) O(1) Priority Heap
LinkedList O(1) O(1) O(1) O(1) O(1) Array
ArrayDequeue O(1) O(1) O(1) O(n) O(1) Linked List
ConcurrentLinkedQueue O(1) O(1) O(1) O(n) O(n) Linked List
ArrayBlockingQueue O(1) O(1) O(1) O(n) O(1) Array
PriorirityBlockingQueue O(log n) O(1) O(log n) O(n) O(1) Priority Heap
SynchronousQueue O(1) O(1) O(1) O(n) O(1) None!
DelayQueue O(log n) O(1) O(log n) O(n) O(1) Priority Heap
LinkedBlockingQueue O(1) O(1) O(1) O(n) O(1) Linked List
Map Get ContainsKey Next Data Structure
HashMap O(1) O(1) O(h / n) Hash Table
LinkedHashMap O(1) O(1) O(1) Hash Table + Linked List
IdentityHashMap O(1) O(1) O(h / n) Array
WeakHashMap O(1) O(1) O(h / n) Hash Table
EnumMap O(1) O(1) O(1) Array
TreeMap O(log n) O(log n) O(log n) Red-black tree
ConcurrentHashMap O(1) O(1) O(h / n) Hash Tables
ConcurrentSkipListMap O(log n) O(log n) O(1) Skip List

JAVA Collections Framework

alt text

Source: Suryaprakash R.

Sort Algorithm Comparison

alt text

Source: MCN Professionals

Contributors

Hieu Tran (trantrunghieu7492@gmail.com)