Notes on Coding Interviews

• Search on YouTube.
• Practice. Practice. Practice.
• Practice a lot of problems? Not so effective.
• Effective way: build up your knowledge from Leetcode.
• Organize classical problems into several categories.
• Excellent example: https://cspiration.com/leetcodeClassification#103.
• My 5 categories: (All-in-one)[doc]
• Foundations: [doc]
• Array
• String
• Math
• Data Structure: [doc]
• Stack
• PriorityQueue
• LinkedList
• Binary Search Tree
• Advanced Design: [doc]
• Backtracking
• Dynamic Programming (too many dissimilar problems, and hard to prepare)
• Union Find
• Trie
• Graph Algorithms: [doc]
• Graph
• Tree
• DFS & BFS
• Topological Sort
• Selected Topics: [doc]
• System Design
• Random
• Matrix
• Bit Manipulation
• Computational Geometry
• Read articles in the Discuss.
• Identify all possible solutions
• Different algorithms (from brute force to effective algorithms).
• Same algorithm with different implementations (e.g., segment tree).
• (My documents are not completed. Try to build up your own documents.)
• Could analyze time complexity and space complexity of each solution.
• Analyze line by line.
• Understand all details of build-in libraries.
• Know which solution is the best under certain assumption.
• Official solutions are not always concise (and the best). But it must be correct.
• Improve your code review ability.
• Read codes in the Submission (if possible).
• Not always correct.
• Learn from undocumented solutions. Need more time to understand.
• Write down your concise code in your style.
• About 20 ~ 40 lines in Java.
• Concise but not tricky. Tricky codes are not easy to remember.
• Possible to reproduce in the real interview.
• Lengthy codes might be regarded as messy codes. 
• Just copy or imitate other's code. 
• Not shame.
• Save your time.
• Align to your style (e.g., binary search, naming convention and so on).
• Practice makes perfect.
• Identify your weakness.
• Could prove the correctness of your code.
• Demonstrate your codes line by line.
• Design meaningful test cases.