| Maximum Number of Points From Grid Queries | Hard | | |
| Minimum Cost Walk in Weighted Graph | Hard | | |
| Recover a Tree From Preorder Traversal | Hard | amazon
linkedin | |
| Smallest sparse number greater than or equal to N | Hard | oracle | |
| Making A Large Island | Hard | amazon
facebook
google
uber | |
| Divide Nodes Into the Maximum Number of Groups | Hard | | |
| Maximum Employees to Be Invited to a Meeting | Hard | | |
| Balance Parentheses with Minimum Insertions and Deletions | Hard | facebook | |
| Count elements in range in sorted matrix | Hard | google | |
| Divide array into two subsets with minimum difference | Hard | microsoft | |
| Split string into fewest palindromic substrings | Hard | google | |
| Alice Joins Probability Student Club by Calculating Expected Values of Probabilistic Games | Hard | two-sigma | |
| Length of the longest path in a weighted tree | Hard | uber | |
| Minimum Cost to Make at Least One Valid Path in a Grid | Hard | google | |
| Sort a list using reverse sublist operation | Hard | | |
| Solve System of Linear Addition Equations | Hard | google | |
| Key-Value Store with Max Key Query | Hard | google | |
| Implement Quack Data Structure with Three Stacks | Hard | google | |
| Binary Tree Depth from Parenthesized String Representation | Hard | linkedin | |
| Queue using Set of Fixed-Length Arrays | Hard | netflix | |
| Implement 3 stacks in 1 list | Hard | microsoft | |
| Find all starting indices of anagrams of a word in a string | Hard | | |
| Find Minimum Diameter After Merging Two Trees | Hard | | |
| Maximum Number of K-Divisible Components | Hard | | |
| Alien Dictionary | Hard | airbnb
amazon
apple
bloomberg
cohesity
doordash
facebook
flipkart
google
microsoft
pinterest
pocket-gems
snapchat
square
twitter
uber
vmware | |
| Amount of New Area Painted Each Day | Hard | | |
| Convert Binary Tree into Threaded Binary Tree | Hard | | |
| Create Sorted Array through Instructions | Hard | | |
| De Bruijn Sequence | Hard | LinkedIn | |
| Delivering Boxes from Storage to Ports | Hard | | |
| Falling Squares | Hard | amazon
square
uber | |
| Fancy Sequence | Hard | | |
| Find a Value of a Mysterious Function Closest to Target | Hard | | |
| Longest Substring of One Repeating Character | Hard | | |
| Minimum Possible Integer After at Most K Adjacent Swaps On Digits | Hard | | |
| My Calendar 3 | Hard | amazon
google | |
| Rectangle Area 2 | Hard | google
sumologic | |
| Strange Printer | Hard | netease | |
| Apply Operations on Array to Maximize Sum of Squares | Hard | | |
| Beautiful Pairs | Hard | | |
| Block Placement Queries | Hard | | |
| Bricks Falling When Hit | Hard | google | |
| Build Binary Expression Tree From Infix Expression | Hard | | |
| Build the Equation | Hard | | |
| Check if DFS Strings Are Palindromes | Hard | | |
| Check If String Is Transformable With Substring Sort Operations | Hard | | |
| Check if There Is a Valid Parentheses String Path | Hard | | |
| Checking Existence of Edge Length Limited Paths II | Hard | | |
| Choose Numbers From Two Arrays in Range | Hard | | |
| Closest Room | Hard | | |