Algorithm/System Design Practice

Supported Language

Miscellaneous

easy

`Problem List`	`Java`	`Python`	`C++`	`Swift`	`JavaScript`	`Scala`	`Go`
Binary Watch	`Solution` ~~`Test`~~	`Solution` `Test`	`Solution` `Test`	`Solution` `Test`	`Solution` `Test`	`Solution` `Test`	`Solution` `Test`
Roman Digits	`Solution` `Test`	`Solution` `Test`	`Solution` `Test`	`Solution` `Test`	`Solution` `Test`		`Solution` `Test`
Valid Anagram	`Solution` `Test`	`Solution` `Test`	`Solution` ~~`Test`~~	`Solution` `Test`	`Solution` `Test`	`Solution` `Test`	`Solution` `Test`

Medium

`Problem List`	`Java`	`Python`	`C++`	`Swift`	`JavaScript`	`Scala`	`Go`
Pouring Water	`Solution` ~~`Test`~~
RankTeams	`Solution` ~~`Test`~~

Hard

`Problem List`	`Java`	`C++`	`Swift`
Best Time to Buy and Sell Stock(I, II, III, IV, Cooldown, Fee)	`Solution` `Test`	`Solution` `Test`	`Solution` `Test`
List Of List Iterator	`Solution` `Test`
Iterable Iterator	`Solution` `Test`

Array

easy

`Problem List`	`Java`	`Python`	`C++`	`Scala`	`Go`
Rotate Array	`Solution` `Test`	`Solution` `Test`	`Solution` `Test`	`Solution` `Test`	`Solution` `Test`
Reverse Vowels of a String	`Solution` ~~`Test`~~	`Solution` `Test`			`Solution` `Test`
Move Zero	`Solution` `Test`				`Solution` `Test`

Medium

`Problem List`	`Java`	`Python`	`C++`	`Swift`	`JavaScript`	`Scala`	`Go`
Zigzag Conversion	`Solution` `Test`	`Solution` `Test`	`Solution` `Test`	`Solution` `Test`	`Solution` `Test`	`Solution` `Test`	`Solution` `Test`
Subarray Sums Divisible by K	`Solution` ~~`Test`~~
Number of Students Doing Homework at a Given Time	`Solution` ~~`Test`~~
Make Two Arrays Equal by Reversing Sub-arrays	`Solution` ~~`Test`~~
Maximum Area of a Piece of Cake After Horizontal and Vertical Cuts	`Solution` ~~`Test`~~
Diagonal Traverse II	`Solution` ~~`Test`~~
Advance Shuffle	`Solution` ~~`Test`~~
Bubble Switcher II III	`Solution` ~~`Test`~~
Invalid Transaction	`Solution` ~~`Test`~~
Randomize Collection	`Solution` ~~`Test`~~
Reduce Array Size to Half	`Solution` ~~`Test`~~
Sum Subarray Minimums	`Solution` ~~`Test`~~
Find All Duplicates in an Array `Solution` ~~`Test`~~
Check If All 1's Are at Least Length K Places Away	`Solution` ~~`Test`~~
Number of Sub-arrays of Size K and Average Greater than or Equal to Threshold	`Solution` ~~`Test`~~
Unique Paths I II	`Solution` ~~`Test`~~
Array of Doubled Pairs	`Solution` ~~`Test`~~
Get Equal Substrings Within Budget	`Solution` ~~`Test`~~
Maximum Points You Can Obtain from Cards	`Solution` ~~`Test`~~
Count Servers that Communicate	`Solution` ~~`Test`~~
Longest Turbulent Subarray	`Solution` ~~`Test`~~
Queries on a Permutation With Key	`Solution` ~~`Test`~~
Count Number of Teams	`Solution` ~~`Test`~~
Cinema Seat Allocation	`Solution` ~~`Test`~~
Friends Of Appropriate Ages	`Solution` ~~`Test`~~
Global and Local Inversions	`Solution` ~~`Test`~~
Sum of Mutated Array Closest to Target	`Solution` ~~`Test`~~
Lonely Pixel I II	`Solution` ~~`Test`~~
Construct Binary Tree from Inorder and Postorder Traversal	`Solution` ~~`Test`~~
Longest Continuous Subarray With Absolute Diff Less Than or Equal to Limit	`Solution` ~~`Test`~~
Subarray Sum Equals K	`Solution` ~~`Test`~~
Maximum Sum Circular Subarray	`Solution` ~~`Test`~~
Divide Array in Sets of K Consecutive Numbers	`Solution` ~~`Test`~~
Grumpy Bookstore Owner	`Solution` ~~`Test`~~
Corporate Flight Bookings	`Solution` ~~`Test`~~
Queens That Can Attack the King	`Solution` ~~`Test`~~
Remove Sub-Folders from the Filesystem	`Solution` ~~`Test`~~
Uncrossed Lines	`Solution` ~~`Test`~~
Longest Line of Consecutive One in Matrix	`Solution` ~~`Test`~~
Split Array with Equal Sum	`Solution` ~~`Test`~~
Teemo Attacking	`Solution` ~~`Test`~~
Number of Subarrays with Bounded Maximum	`Solution` ~~`Test`~~
Minimum Increment to Make Array Unique	`Solution` ~~`Test`~~
Leftmost Column with at Least a One	`Solution` ~~`Test`~~
Previous Permutation With One Swap	`Solution` ~~`Test`~~
Decrease Elements To Make Array Zigzag	`Solution` ~~`Test`~~
Count Square Submatrices with All Ones	`Solution` ~~`Test`~~
Sort the Matrix Diagonally	`Solution` ~~`Test`~~
Subrectangle Queries	`Solution` ~~`Test`~~
Reveal Cards In Increasing Order	`Solution` ~~`Test`~~
Task Scheduler	`Solution` ~~`Test`~~
Count Triplets That Can Form Two Arrays of Equal XOR	`Solution` ~~`Test`~~
Array Nesting	`Solution` ~~`Test`~~
Shortest Word Distance III	`Solution` ~~`Test`~~
Maximum Sum of Two Non-Overlapping Subarrays	`Solution` ~~`Test`~~
Filter Restaurants by Vegan-Friendly, Price and Distance	`Solution` ~~`Test`~~
Beautiful Arrangement I II	`Solution` ~~`Test`~~
Capacity To Ship Packages Within D Days	`Solution` ~~`Test`~~
Best Sightseeing Pair	`Solution` ~~`Test`~~
Minimum Domino Rotations For Equal Row	`Solution` ~~`Test`~~
Number of Matching Subsequences	`Solution` ~~`Test`~~
Candy Crush	`Solution` ~~`Test`~~
Combination Sum II III	`Solution` ~~`Test`~~
Range Addition	`Solution` ~~`Test`~~
Snapshot Array	`Solution` ~~`Test`~~
Max Area of Island	`Solution` ~~`Test`~~
Avoid Flood in The City	`Solution` ~~`Test`~~
Design Twitter	`Solution` ~~`Test`~~

Hard

`Problem List`	`Java`	`Python`	`C++`	`Scala`	`Go`	`Rust`	`Kotlin`
Remove duplicates int from array	`Solution` `Test`	`Solution` `Test`	`Solution` `Test`	`Solution` `Test`	`Solution` `Test`
Print Pattern	`Solution` `Test`		`Solution` `Test`		`Solution` `Test`
Sliding Windows	`Solution` `Test`		`Solution` `Test`		`Solution` `Test`
Minimum Size Subarray Sum	`Solution` `Test`
Continuous Subarray Sum	`Solution` `Test`
Subarray Product Less Than K	`Solution` `Test`		`Solution` `Test`
Longest Palindrome Length		`Solution` `Test`
Merge Intervals		`Solution` `Test`
Wiggle Sort	`Solution` `Test`
Brick Wall	`Solution`
Next Greater Element	`Solution` `Test`
Search for a Range	`Solution` `Test`
1-bit and 2-bit Characters	`Solution` `Test`
Count of Smaller Numbers After Self		`Solution` `Test`
Insert Interval	`Solution` `Test`	`Solution` `Test`
Word Search				`Solution` `Test`
Intersection of Arrays	`Solution` ~~`Test`~~	`Solution` `Test`		`Solution` `Test`
Longest Consecutive Sequence			`Solution` `Test`
Largest Number			`Solution` `Test`
Candies			`Solution` `Test`
Water			`Solution` `Test`
Gas Station			`Solution` `Test`
Implement queue with array	`Solution` `Test`
Most Population Year							`Solution`
Replace Elements with Greatest Element on Right Side	`Solution` ~~`Test`~~
Reverse Only Letters	`Solution` ~~`Test`~~
Pour Water	`Solution` ~~`Test`~~
Find Smallest Letter Greater Than Target	`Solution` ~~`Test`~~
Maximum Width Ramp	`Solution` ~~`Test`~~
Pancake Sorting	`Solution` ~~`Test`~~
Reverse Pairs						`Solution`
Median of Two sorted arrays						`Solution`

Matrix

`Problem List`	`Java`	`C++`	`Scala`
Minimum steps to G(Facebook)	`Solution` `Test`
Rotate Image	`Solution` `Test`		`Solution` `Test`
Spiral Matrix II	`Solution` `Test`	`Solution` `Test`
Number of Islands	`Solution` `Test`	`Solution` `Test`
Set Zeroes		`Solution` `Test`
Search I		`Solution` `Test`
Search II		`Solution` `Test`
Mine Sweeper	`Solution` `Test`

Linked List

`Problem List`	`Java`	`Go`
Circle	`Solution` `Test`	`Solution` `Test`
Remove reverse kth element	`Solution` `Test`
One diff only(Facebook)	`Solution` ~~`Test`~~
Swap Pairs	`Solution` `Test`
Reorder List	`Solution` `Test`
Odd Even Linked List	`Solution` `Test`
Reverse Nodes in k-Group	`Solution` `Test`
Print Immutable Linked List in Reverse	`Solution` ~~`Test`~~

Stack

`Problem List`	`Java`	`Python`	`C++`
Min Stack(Netflix)	`Solution` `Test`	`Solution` `Test`	`Solution` `Test`
Wiggle Subsequence	`Solution` `Test`		`Solution` `Test`
Max Chunks To Make Sorted			`Solution` `Test`
Calculator			`Solution` `Test`

Math

`Problem List`	`Java`	`Python`	`C++`	`JavaScript`	`Scala`	`Go`	`Rust`
Add One(Apple)	`Solution` `Test`	`Solution` `Test`	`Solution` `Test`	`Solution` `Test`	`Solution` `Test`	`Solution` `Test`
Sort by one(GE)	`Solution` `Test`	`Solution` `Test`	`Solution` `Test`	`Solution` `Test`	`Solution` `Test`	`Solution` `Test`
Reverse Integer	`Solution` `Test`		`Solution` `Test`
One's Number	`Solution`		`Solution` `Test`
Add Two Numbers	`Solution` `Test`		`Solution` `Test`
ATOI	`Solution` ~~`Test`~~		`Solution` `Test`
Sum(Two Sum, Three Sum, Three Sum Closest, 4 Sum)	`Solution` ~~`Test`~~
Ugly Number	`Solution` `Test`		`Solution` `Test`
Count Numbers with Unique Digits	`Solution` ~~`Test`~~
Prime Sum(Facebook)	`Solution` ~~`Test`~~
Big Integer(Facebook)	`Solution` `Test`
Single Number	`Solution` `Test`
Arranging Coins			`Solution` `Test`
Perfect Number					`Solution` `Test`	`Solution` `Test`
Prime Number of Set Bits in Binary Representation						`Solution` `Test`
Sequential Digits	`Solution` ~~`Test`~~
Consecutive Numbers Sum							`Solution`

Bit Operation

`Problem List`	`Java`	`Python`	`C++`	`Swift`	`Scala`	`Go`
Power Of Four	`Solution` ~~`Test`~~		`Solution` `Test`		`Solution` `Test`	`Solution` `Test`
Single Number	`Solution` ~~`Test`~~	`Solution` `Test`	`Solution` `Test`		`Solution` `Test`	`Solution` `Test`
Swap Two Integer	`Solution` `Test`	~~Python use tuple~~	`Solution` `Test`	~~Swift use tuple~~	~~Scala use tuple~~

Tree

`Problem List`	`Java`	`Python`	`C++`	`Swift`
Binrary Tree Serialization(Apple)	`Solution` `Test`
Binrary Tree Traversal	`Solution` `Test`		`Solution` ~~[`Test`]~~	`Solution` ~~`Test`~~)
Minimum Height Trees	`Solution` ~~`Test`~~
Longest Consecutive Path	`Solution` ~~`Test`~~
Binary Tree Zigzag Level Order Traversal	`Solution` `Test`
Find Duplicate Subtrees	`Solution` `Test`
Longest Path(Facebook)	`Solution` ~~`Test`~~
Balanced Binrary Tree		`Solution` ~~`Test`~~
Add One Row to Tree	`Solution` ~~`Test`~~
Construct String from Binary Tree		`Solution` ~~`Test`~~
Range Sum of BST	`Solution` ~~`Test`~~
Path Sum III	`Solution` ~~`Test`~~
Find Largest Value in Each Tree Row	`Solution` ~~`Test`~~
Deepest Leaves Sum	`Solution` ~~`Test`~~

String

`Problem List`	`Java`	`Python`	`C++`	`Scala`	`Go`	`Rust`
Knuth–Morris–Pratt	`Solution` ~~`Test`~~	`Solution` `Test`	`Solution` `Test`		`Solution` `Test`
Longest Substring Without Repeating Characters	`Solution` ~~`Test`~~
Isomorphic Strings	`Solution` `Test`	`Solution` `Test`
Reverse Words	`Solution` `Test`			`Solution` `Test`	`Solution` `Test`
Interleave(Facebook)	`Solution` ~~`Test`~~
Count cross for reorder array		`Solution` ~~`Test`~~
Minimum Time Difference	`Solution` ~~`Test`~~
Remove K Digits	`Solution` `Test`
Minimum Window Substring	`Solution` `Test`
Z Sort	`Solution` `Test`		`Solution` `Test`
Remove Duplicate Letters	`Solution` `Test`		`Solution` `Test`
Top K Frequent Words			`Solution` `Test`
Decode String			`Solution` `Test`
Minimum Window Substring			`Solution` `Test`
String Matching	`Solution` ~~`Test`~~
Custom Sort String	`Solution` ~~`Test`~~
Shortest Completing Word	`Solution` ~~`Test`~~
Push Dominoes	`Solution` ~~`Test`~~
Regular Expression Matching						`Solution`

Permutation

`Problem List`	`Java`	`Python`	`C++`	`Swift`	`JavaScript`	`Scala`	`Go`
Permutation(Apple)	`Solution` `Test`	`Solution` ~~`Test`~~				`Solution` `Test`

Greedy

`Problem List`	`Java`	`Python`	`C++`	`Swift`	`JavaScript`	`Scala`	`Go`
Permutation(Apple)	`Solution` `Test`

Hint: When it asking maximum, minmum, optimal, this could be a dynamic programming problem

`Problem List`	`Java`	`Python`	`C++`	`Go`
Fibonacci	`Solution` `Test`	`Solution` `Test`	`Solution` `Test`	`Solution` `Test`
Coin Change	`Solution` `Test`		`Solution` `Test`
Knapsack	`Solution` `Test`		`Solution` `Test`
Longest Common Subsequence(Linkedin)	`Solution` `Test`		`Solution` `Test`
Subset to Sum	`Solution` `Test`		`Solution` `Test`
Maximal Square	`Solution` `Test`
Longest Increasing Subsequence	`Solution` `Test`
Largest Rectangle in Histogram	`Solution` `Test`
Wildcard Matching	`Solution` `Test`
Predict Winner	`Solution` `Test`
2 Keys Keyboard	`Solution` ~~`Test`~~
Edit Distance	`Solution` `Test`		`Solution` `Test`
Print House	`Solution` ~~`Test`~~		`Solution` ~~`Test`~~
Maximum Length of Repeated Subarray	`Solution` `Test`
Marbles in Three Baskets	`Solution` `Test`
Split Array With Same Average			`Solution` `Test`
Distinct Subsequences Total			`Solution` `Test`
Decode Ways II	`Solution` ~~`Test`~~
Min Cost Climbing Stairs	`Solution` ~~`Test`~~
heapest Flights Within K Stops	`Solution` ~~`Test`~~

Binary Search

`Problem List`	`Java`	`C++`	`Go`
Binary Search in rotated order array	`Solution` `Test`	`Solution` `Test`	`Solution` `Test`
Lookup Latest Good Version(Facebook)	`Solution` ~~`Test`~~
Random Color(Uber)	`Solution` `Test`

Graph

`Problem List`	`Java`	`Python`	`C++`	`Swift`	`JavaScript`	`Scala`	`Go`
Topology Sort(Apple)	`Solution` `Test`
Dijkstra Algorithm	`Solution` `Test`
Minimum Spanning Tree(Prim, Krusal)	`Solution` `Test`

Geometry

`Problem List`	`Java`	`Python`	`C++`	`Swift`	`JavaScript`	`Scala`	`Go`
Valid Triangle Number	`Solution` ~~`Test`~~
Max Points on a Line	`Solution` `Test`

Data Structure

`Problem List`	`Java`	`C++`
Trie	`Solution` `Test`
LRU(Salesforce/Amazon)	`Solution` `Test`
LFU	`Solution` `Test`
Binary Heap	`Solution` `Test`	`Solution` `Test`
Magic Dictionary	`Solution` `Test`	`Solution` `Test`
Map Sum Pairs	`Solution` `Test`
Find Median from Data Stream		`Solution` ~~`Test`~~
Fenwick Tree		`Solution` ~~`Test`~~
Range Module	`Solution` `Test`
All One	`Solution` ~~`Test`~~
Insert Delete GetRandom O(1)		`Solution` `Test`
Red-Black Tree		`Solution` ~~`Test`~~
Palindrome		`Solution` `Test`
Product of the Last K Numbers	`Solution` ~~`Test`~~
Iterator for Combination	`Solution` ~~`Test`~~

Backtracking

Medium

`Problem List`	`Java`	`Python`	`C++`	`Swift`	`JavaScript`	`Scala`	`Go`
Generate Parentheses	`Solution` `Test`
Pattern Matching	`Solution` `Test`

Hashtable

`Problem List`	`Java`	`Python`	`C++`	`Swift`	`JavaScript`	`Scala`	`Go`
Binary Subarrays With Sum	`Solution` ~~`Test`~~
Rabbits in Forest	`Solution` ~~`Test`~~
Longest String Chain	`Solution` ~~`Test`~~
Sort Characters By Frequency	`Solution` ~~`Test`~~
Sparse Matrix Multiplication	`Solution` ~~`Test`~~

Union and Find

`Problem List`	`Java`	`Python`	`C++`	`Swift`	`JavaScript`	`Scala`	`Go`
Friend Circles	`Solution` ~~`Test`~~

Double Pointer

`Problem List`	`Java`	`Python`	`C++`	`Swift`	`JavaScript`	`Scala`	`Go`
Long Pressed Name	`Solution` ~~`Test`~~
Fruit Into Baskets	`Solution` ~~`Test`~~

Range

`Problem List`	`Java`	`Python`	`C++`	`Swift`	`JavaScript`	`Scala`	`Go`
Smallest Range			`Solution` `Test`

BFS/DFS

`Problem List`	`Java`	`Python`	`C++`	`Swift`	`JavaScript`	`Scala`	`Go`
Super Palindromes	`Solution` ~~`Test`~~
WordLadder	`Solution` ~~`Test`~~
Open the Lock	`Solution` ~~`Test`~~

Design

`Problem List`	`Java`	`Python`	`C++`	`Swift`	`JavaScript`	`Scala`	`Go`
PackageManager	`Solution`
Amazon 1 Amazon 2	`Solution` `Test`		`Solution` `Test`

Advanced algorithm

Design Pattern

Pattern

Creational

`Problem List`	`Java`	`Python`	`C++`	`Swift`
Abstract Factory
Builder
Singleton	Early Initialization	Lazy Initialization	Class holder	Enum

Structural

`Problem List`	`Java`	`Python`	`C++`	`Swift`	`JavaScript`	`Scala`	`Go`
Adapter
Bridge
Composite
Decrorator
Facade
FlyWeight	Generic
Proxy

Behavioral

`Problem List`	`Java`	`Python`	`C++`	`Swift`	`JavaScript`	`Scala`	`Go`
Chain of Responsibility
Command
Iterpreter
Iterator
Mediator
Memento
Observer(Listener)
State
Strategy
Visitor

Anti-Pattern

Multiple Thread Programming

System Design Practice

Concept

Proxies

Load Balancing

Caching

Distributed Cache
MemCached
Redis

Sharding and Data Partition

-[Horizontal partitioning vs Vertical Partitioning]

Deal with Sharing Problem

[Joins and Denormalization]
[Referential integrity]
[Rebalancing]

Consistent Hashing

Copysets

https://web.stanford.edu/~skatti/pubs/usenix13-copysets.pdf

CAP Theorem(Consistency,Availability,Partition Tolerance)

WIKI CAP_theorem

Storage

LSM vs B-Tree Link1

Vector Clock

Protocol

Raft Link1
Paxos Link1

Event Update

-[Long-Polling(pull) vs WebSockets vs Server-Sent Events(push)]

Practice

SQL

`Question`	`My SQL`	`Oracle`	`SQL Server`
Combine Two Tables	`Solution`
Second Highest Salary	`Solution`
Rank Scores	`Solution`
Employees Earning More Than Their Managers	`Solution`
Duplicate Emails	`Solution`
Customers Who Never Order	`Solution`
Rising Temperature	`Solution`

Name		Name	Last commit message	Last commit date
Latest commit History 525 Commits
KTAlgs/src/yan/haibo/array		KTAlgs/src/yan/haibo/array
algorithm_swift		algorithm_swift
c++		c++
go		go
java		java
javascript		javascript
python		python
rust		rust
scala		scala
sql/mysql		sql/mysql
system		system
.gitignore		.gitignore
README.md		README.md
amazon_1.png		amazon_1.png
amazon_2.png		amazon_2.png

billyean/acadia

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Algorithm/System Design Practice

Supported Language

Miscellaneous

easy

Medium

Hard

Array

easy

Medium

Hard

Matrix

Linked List

Stack

Math

Bit Operation

Tree

String

Permutation

Greedy

Binary Search

Graph

Geometry

Data Structure

Backtracking

Medium

Hashtable

Union and Find

Double Pointer

Range

BFS/DFS

Design

Advanced algorithm

Design Pattern

Pattern

Creational

Structural

Behavioral

Anti-Pattern

Multiple Thread Programming

System Design Practice

Concept

Proxies

Load Balancing

Caching

Sharding and Data Partition

Consistent Hashing

Copysets

CAP Theorem(Consistency,Availability,Partition Tolerance)

Storage

Vector Clock

Protocol

Event Update

Practice

SQL

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