Company: X
- Alien Dictionary
- Best Meeting Point
- Binary Gap
- Count Sub Islands
- Design Authentication Manager
- Design Skiplist
- Design Twitter
- Finding the Users Active Minutes
- Flatten 2D Vector
- Flatten Nested List Iterator
- Happy Number
- Implement Trie (Prefix Tree)
- Insert Delete GetRandom O(1)
- Integer to Roman
- Kth Smallest Element in a Sorted Matrix
- Lowest Common Ancestor of a Binary Search Tree
- LRU Cache
- Masking Personal Information
- Max Points on a Line
- Merge Intervals
- Merge k Sorted Lists
- Minimum Elements to Add to Form a Given Sum
- Minimum Genetic Mutation
- Minimum Number of Steps to Make Two Strings Anagram
- Multiply Strings
- Number of Black Blocks
- Number of Connected Components in an Undirected Graph
- One Edit Distance
- Pascal's Triangle
- Permutation Sequence
- Process Tasks Using Servers
- Random Pick with Weight
- Regular Expression Matching
- Remove All Occurrences of a Substring
- Reverse Linked List
- The Skyline Problem
- Time Needed to Buy Tickets
- Trapping Rain Water II
- Trapping Rain Water
- Tweet Counts Per Frequency
- Valid Parentheses
- Validate IP Address
- Wildcard Matching
- Word Break II