LeetCode

If you like this project, please leave me a star. ★

"For coding interview preparation, LeetCode is one of the best online resource providing a rich library of more than 300 real coding interview questions for you to practice from using one of the 7 supported languages - C, C++, Java, Python, C#, JavaScript, Ruby."

Algorithms

For problems 1 to 999

For problems 1000 to 1999

For problems 2000 to 2999

For problems 3000 to 3999

Database

#	Title	Solutions	Video	Difficulty	Tag
1757	Recyclable and Low Fat Products	Solution		Easy
1729	Find Followers Count	Solution		Easy
1709	Biggest Window Between Visits	Solution		Medium
1693	Daily Leads and Partners	Solution		Easy
1683	Invalid Tweets	Solution		Easy
1677	Product's Worth Over Invoices	Solution		Easy
1667	Fix Names in a Table	Solution		Easy
1661	Average Time of Process per Machine	Solution		Easy
1633	Percentage of Users Attended a Contest	Solution		Easy
1623	All Valid Triplets That Can Represent a Country	Solution		Easy
1607	Sellers With No Sales	Solution		Easy
1596	The Most Frequently Ordered Products for Each Customer	Solution		Medium
1571	Warehouse Manager	Solution		Easy
1587	Bank Account Summary II	Solution		Easy
1581	Customer Who Visited but Did Not Make Any Transactions	Solution		Easy
1565	Unique Orders and Customers Per Month	Solution		Easy
1543	Fix Product Name Format	Solution		Easy
1527	Patients With a Condition	Solution		Easy
1517	Find Users With Valid E-Mails	Solution		Easy
1511	Customer Order Frequency	Solution		Easy
1495	Friendly Movies Streamed Last Month	Solution		Easy
1435	Create a Session Bar Chart	Solution		Easy
1484	Group Sold Products By The Date	Solution		Easy
1445	Apples & Oranges	Solution		Medium
1407	Top Travellers	Solution		Easy
1393	Capital Gain/Loss	Solution		Easy
1384	Total Sales Amount by Year	Solution		Hard
1378	Replace Employee ID With The Unique Identifier	Solution		Easy
1371	The Number of Employees Which Report to Each Employee	Solution		Easy
1369	Get the Second Most Recent Activity	Solution		Hard
1364	Number of Trusted Contacts of a Customer	Solution		Medium
1355	Activity Participants	Solution		Medium
1350	Students With Invalid Departments	Solution		Easy
1341	Movie Rating	Solution		Medium
1327	List the Products Ordered in a Period	Solution		Easy
1322	Ads Performance	Solution		Easy
1308	Running Total for Different Genders	Solution		Medium
1303	Find the Team Size	Solution		Easy
1294	Weather Type in Each Country	Solution		Easy
1285	Find the Start and End Number of Continuous Ranges	Solution		Medium
1280	Students and Examinations	Solution	📺	Easy
1270	All People Report to the Given Manager	Solution		Medium
1251	Average Selling Price	Solution		Easy
1241	Number of Comments per Post	Solution		Easy
1211	Queries Quality and Percentage	Solution		Easy
1179	Reformat Department Table	Solution		Easy
1173	Immediate Food Delivery I	Solution		Easy
1148	Article Views I	Solution		Easy
1142	User Activity for the Past 30 Days II	Solution		Easy
1141	User Activity for the Past 30 Days I	Solution		Easy
1113	Reported Posts	Solution		Easy
1084	Sales Analysis III	Solution		Easy
1083	Sales Analysis II	Solution		Easy
1082	Sales Analysis I	Solution		Easy
1076	Project Employees II	Solution		Easy
1075	Project Employees I	Solution		Easy
1069	Product Sales Analysis II	Solution		Easy
1068	Product Sales Analysis I	Solution		Easy
1050	Actors and Directors Who Cooperated At Least Three Times	Solution		Easy
627	Swap Salary	Solution		Easy
626	Exchange Seats	Solution		Medium
620	Not Boring Movies	Solution		Easy
619	Biggest Single Number	Solution		Easy
618	Students Report By Geography	Solution		Hard	Session Variables
615	Average Salary: Departments VS Company	Solution		Hard
614	Second Degree Follower	Solution		Medium	Inner Join
613	Shortest Distance in a Line	Solution		Easy
612	Shortest Distance in a Plane	Solution		Medium
610	Triangle Judgement	Solution		Easy
608	Tree Node	Solution		Medium	Union
607	Sales Person	Solution		Easy
603	Consecutive Available Seats	Solution		Easy
602	Friend Requests II: Who Has the Most Friends	Solution		Medium
601	Human Traffic of Stadium	Solution		Hard
597	Friend Requests I: Overall Acceptance Rate	Solution		Easy
596	Classes More Than 5 Students	Solution		Easy
595	Big Countries	Solution		Easy
586	Customer Placing the Largest Number of Orders	Solution		Easy
585	Investments in 2016	Solution		Medium
584	Find Customer Referee	Solution		Easy
580	Count Student Number in Departments	Solution		Medium	Left Join
578	Get Highest Answer Rate Question	Solution		Medium
577	Employee Bonus	Solution		Easy
574	Winning Candidate	Solution		Medium
571	Find Median Given Frequency of Numbers	Solution		Hard
570	Managers with at Least 5 Direct Reports	Solution		Medium
569	Median Employee Salary	Solution		Hard
534	Game Play Analysis III	Solution		Easy
512	Game Play Analysis II	Solution		Easy
511	Game Play Analysis I	Solution		Easy
262	Trips and Users	Solution		Hard	Inner Join
197	Rising Temperature	Solution		Easy
196	Delete Duplicate Emails	Solution		Easy
185	Department Top Three Salaries	Solution		Hard
184	Department Highest Salary	Solution		Medium
183	Customers Who Never Order	Solution		Easy
182	Duplicate Emails	Solution		Easy
181	Employees Earning More Than Their Managers	Solution		Easy
180	Consecutive Numbers	Solution		Medium
178	Rank Scores	Solution		Medium
177	Nth Highest Salary	Solution		Medium
176	Second Highest Salary	Solution		Easy
175	Combine Two Tables	Solution		Easy

Shell

#	Title	Solutions	Video	Difficulty	Tag
195	Tenth Line	Solution		Easy
194	Transpose File	Solution		Medium
193	Valid Phone Numbers	Solution		Easy
192	Word Frequency	Solution		Medium

Contributing

Your ideas/fixes/algorithms are more than welcome!

0. Please make sure your PR builds after submitting! Check out here: https://travis-ci.org/github/fishercoder1534/Leetcode/pull_requests and look for your PR build.
1. Fork this repo
2. Clone your forked repo (git clone https://github.com/YOUR_GITHUB_USERNAME/Leetcode.git) onto your local machine
3. cd into your cloned directory, create your feature branch (git checkout -b my-awesome-fix)
4. git add your desired changes to this repo
5. Commit your changes (git commit -m 'Added some awesome features/fixes')
6. Push to the branch (git push origin my-awesome-feature)
7. Open your forked repo on Github website, create a new Pull Request to this repo!

Best way to open this project

1. Install IntelliJ on your machine, either CE or UE.
2. git clone this repo to your local disk
3. import this project as a new project (does need to be imported as a gradle project)
4. If you run into "Could not determine Java version using executable ..." error, use local gradle distribution: "/usr/local/Cellar/gradle/4.8.1/libexec/" instead of the default one. More details, see this question on Stackoverflow.