Q3
Joins
49 stations · 8.1hInner, left, self and cross joins, and finding rows that have no match. 49 interview problems explained by Everyday Data Science (8.1h of video), grouped into 4 patterns such as Self join, Rows with no match (anti join), Cross join (all combinations).
Start this line →- Self join18
- Rows with no match (anti join)3
- Cross join (all combinations)4
- Multi-table join17
- Other21
Self join
0 of 18 passed- Employees Earning More Than Their ManagersLC 181 · 15:09EasyGoogle · Amazon · +8 more companiesLeetCode ↗ (opens in a new tab)
- All People Report to the Given ManagerLC 1270 · 26:26 · LeetCode PremiumMediumGoogle · AmazonLeetCode ↗ (opens in a new tab)
- The Number of Employees Which Report to Each EmployeeLC 1731 · 7:01EasyGoogle · Amazon · +3 more companiesLeetCode ↗ (opens in a new tab)
- The Number of Seniors and Juniors to Join the CompanyLC 2004 · 20:30 · LeetCode PremiumHardLeetCode ↗ (opens in a new tab)
- Leetcodify Similar FriendsLC 1919 · 7:30 · LeetCode PremiumHardSpotifyLeetCode ↗ (opens in a new tab)
- Leetcodify Friends RecommendationsLC 1917 · 9:07 · LeetCode PremiumHardSpotifyLeetCode ↗ (opens in a new tab)
- Strong FriendshipLC 1949 · 11:13 · LeetCode PremiumMediumGoogle · MetaLeetCode ↗ (opens in a new tab)
- The Number of Seniors and Juniors to Join the Company IILC 2010 · 8:11 · LeetCode PremiumHardLeetCode ↗ (opens in a new tab)
- Friends With No Mutual FriendsLC 3058 · 8:47 · LeetCode PremiumMediumLeetCode ↗ (opens in a new tab)
Rows with no match (anti join)
0 of 3 passed- Customer Who Visited but Did Not Make Any TransactionsLC 1581 · 7:11EasyGoogle · Amazon · +4 more companiesLeetCode ↗ (opens in a new tab)
- Friends With No Mutual FriendsLC 3058 · 8:47 · LeetCode PremiumMediumLeetCode ↗ (opens in a new tab)
Cross join (all combinations)
0 of 4 passed- Students and ExaminationsLC 1280 · 20:13EasyGoogle · Amazon · +5 more companiesLeetCode ↗ (opens in a new tab)
- All the Matches of the LeagueLC 2339 · 5:20 · LeetCode PremiumEasyMicrosoftLeetCode ↗ (opens in a new tab)
- All Valid Triplets That Can Represent a CountryLC 1623 · 6:23 · LeetCode PremiumEasyAmazonLeetCode ↗ (opens in a new tab)
Multi-table join
0 of 17 passed- The Number of Seniors and Juniors to Join the CompanyLC 2004 · 20:30 · LeetCode PremiumHardLeetCode ↗ (opens in a new tab)
- Number of Trusted Contacts of a CustomerLC 1364 · 11:05 · LeetCode PremiumMediumRobloxLeetCode ↗ (opens in a new tab)
- Strong FriendshipLC 1949 · 11:13 · LeetCode PremiumMediumGoogle · MetaLeetCode ↗ (opens in a new tab)
- The Number of Seniors and Juniors to Join the Company IILC 2010 · 8:11 · LeetCode PremiumHardLeetCode ↗ (opens in a new tab)
- Friends With No Mutual FriendsLC 3058 · 8:47 · LeetCode PremiumMediumLeetCode ↗ (opens in a new tab)
Other
0 of 21 passed- Combine Two TablesLC 175 · 13:24EasyGoogle · Amazon · +6 more companiesLeetCode ↗ (opens in a new tab)
- Replace Employee ID With The Unique IdentifierLC 1378 · 4:26EasyGoogle · Amazon · +7 more companiesLeetCode ↗ (opens in a new tab)
- Product Sales Analysis ILC 1068 · 3:57EasyGoogle · Amazon · +5 more companiesLeetCode ↗ (opens in a new tab)
- Accepted Candidates From the InterviewsLC 2041 · 6:37 · LeetCode PremiumMediumLeetCode ↗ (opens in a new tab)
- Number of Times a Driver Was a PassengerLC 2238 · 8:15 · LeetCode PremiumMediumAmazonLeetCode ↗ (opens in a new tab)
- Market Analysis ILC 1158 · 9:08MediumGoogle · Amazon · +2 more companiesLeetCode ↗ (opens in a new tab)
- Countries You Can Safely Invest InLC 1501 · 15:09 · LeetCode PremiumMediumLeetCode ↗ (opens in a new tab)
- Count Student Number in DepartmentsLC 580 · 8:38 · LeetCode PremiumMediumXLeetCode ↗ (opens in a new tab)
- Count the Number of ExperimentsLC 1990 · 15:09 · LeetCode PremiumMediumLeetCode ↗ (opens in a new tab)
- Shortest Distance in a PlaneLC 612 · 11:28 · LeetCode PremiumMediumMetaLeetCode ↗ (opens in a new tab)
- Calculate the Influence of Each SalespersonLC 2372 · 7:42 · LeetCode PremiumMediumLeetCode ↗ (opens in a new tab)
All 49 stations in order
- 1.Combine Two Tables (LeetCode 175)
- 2.Employees Earning More Than Their Managers (LeetCode 181)
- 3.Employee Bonus (LeetCode 577)
- 4.Shortest Distance in a Line (LeetCode 613)
- 5.Students and Examinations (LeetCode 1280)
- 6.Replace Employee ID With The Unique Identifier (LeetCode 1378)
- 7.Top Travellers (LeetCode 1407)
- 8.NPV Queries (LeetCode 1421)
- 9.Warehouse Manager (LeetCode 1571)
- 10.Customer Who Visited but Did Not Make Any Transactions (LeetCode 1581)
- 11.Grand Slam Titles (LeetCode 1783)
- 12.All People Report to the Given Manager (LeetCode 1270)
- 13.Product Sales Analysis I (LeetCode 1068)
- 14.Count Apples and Oranges (LeetCode 1715)
- 15.Accepted Candidates From the Interviews (LeetCode 2041)
- 16.Number of Times a Driver Was a Passenger (LeetCode 2238)
- 17.Market Analysis I (LeetCode 1158)
- 18.Rectangles Area (LeetCode 1459)
- 19.Ad-Free Sessions (LeetCode 1809)
- 20.Countries You Can Safely Invest In (LeetCode 1501)
- 21.Count Student Number in Departments (LeetCode 580)
- 22.Count the Number of Experiments (LeetCode 1990)
- 23.The Number of Employees Which Report to Each Employee (LeetCode 1731)
- 24.The Number of Seniors and Juniors to Join the Company (LeetCode 2004)
- 25.All the Matches of the League (LeetCode 2339)
- 26.Product's Worth Over Invoices (LeetCode 1677)
- 27.Shortest Distance in a Plane (LeetCode 612)
- 28.Calculate the Influence of Each Salesperson (LeetCode 2372)
- 29.Total Traveled Distance (LeetCode 2837)
- 30.Form a Chemical Bond (LeetCode 2480)
- 31.Second Degree Follower (LeetCode 614)
- 32.Tournament Winners (LeetCode 1194)
- 33.All Valid Triplets That Can Represent a Country (LeetCode 1623)
- 34.Server Utilization Time (LeetCode 3126)
- 35.Number of Trusted Contacts of a Customer (LeetCode 1364)
- 36.Page Recommendations II (LeetCode 1892)
- 37.Leetcodify Similar Friends (LeetCode 1919)
- 38.Leetcodify Friends Recommendations (LeetCode 1917)
- 39.Strong Friendship (LeetCode 1949)
- 40.The Number of Seniors and Juniors to Join the Company II (LeetCode 2010)
- 41.Calculate Product Final Price (LeetCode 3293)
- 42.Friends With No Mutual Friends (LeetCode 3058)
- 43.Find Students Who Improved (LeetCode 3421)
- 44.Team Dominance by Pass Success (LeetCode 3384)
- 45.Find Overlapping Shifts (LeetCode 3262)
- 46.Find Overlapping Shifts II (LeetCode 3268)
- 47.Find Product Recommendation Pairs (LeetCode 3521)
- 48.Find Books with No Available Copies (LeetCode 3570)
- 49.Find Category Recommendation Pairs (LeetCode 3554)