Appendix B — Appendix B: LeetCode Index

Appendix B: LeetCode Index

Every LeetCode problem referenced in this book, organized by chapter. Each links to the problem; many also have my own submission archive at ~/leetcode-submissions/ for comparison.

B.1 Problems by chapter

B.1.1 Chapter 2 — STL vector

B.1.2 Chapter 3 — STL set/map/stack/queue

B.1.3 Chapter 4 — Pointers

B.1.7 Chapter 14 — Sorting

B.1.8 Chapter 16 — Linked Lists

B.1.9 Chapter 17 — Binary Trees Intro

B.1.10 Chapter 18 — Advanced Recursion

B.1.11 Chapter 22 — Trees revisited

Binary Tree Inorder Traversal (#94)
Binary Tree Level Order Traversal (#102)

B.1.12 Chapter 23 — BST delete

B.1.13 Chapter 25 — Heaps

B.1.14 Chapter 26 — Graphs BFS/DFS

Number of Islands (#200)
Flood Fill (#733)
Number of Connected Components in an Undirected Graph (#323)
Course Schedule (#207)

B.1.15 Chapter 27 — Shortest paths and MST

B.1.16 Chapter 28 — Hash tables

Group Anagrams (#49)
LRU Cache (#146)
Longest Substring Without Repeating Characters (#3)

B.1.17 Chapter 29 — Balanced trees

Convert Sorted Array to Binary Search Tree (#108)
Balanced Binary Tree (#110)

B.1.18 Chapter 31 — Divide and conquer

Merge k Sorted Lists (#23)
Pow(x, n) (#50)
Count of Smaller Numbers After Self (#315)

B.1.19 Chapter 32 — Greedy

Assign Cookies (#455)
Jump Game (#55)
Jump Game II (#45)
Gas Station (#134)
Best Time to Buy and Sell Stock II (#122)
Task Scheduler (#621)

B.1.20 Chapter 33 — DP I

B.1.21 Chapter 34 — DP II

B.1.22 Chapter 37 — Regex

Longest Common Prefix (#14)

B.2 By difficulty (rough)

B.2.1 Easy

#1 Two Sum
#9 Palindrome Number
#20 Valid Parentheses
#21 Merge Two Sorted Lists
#70 Climbing Stairs
#88 Merge Sorted Array
#104 Maximum Depth of Binary Tree
#141 Linked List Cycle
#198 House Robber
#206 Reverse Linked List
#226 Invert Binary Tree
#344 Reverse String
#509 Fibonacci Number
#704 Binary Search
#876 Middle of the Linked List

B.2.2 Medium

#3 Longest Substring Without Repeating Characters
#45 Jump Game II
#49 Group Anagrams
#62 Unique Paths
#75 Sort Colors
#78 Subsets
#98 Validate BST
#102 Level Order Traversal
#122 Best Time to Buy and Sell Stock II
#133 Clone Graph
#134 Gas Station
#146 LRU Cache
#200 Number of Islands
#207 Course Schedule
#210 Course Schedule II
#215 Kth Largest
#300 Longest Increasing Subsequence
#322 Coin Change
#347 Top K Frequent
#416 Partition Equal Subset Sum
#450 Delete BST Node
#543 Diameter of Binary Tree
#621 Task Scheduler
#743 Network Delay
#912 Sort an Array
#1143 Longest Common Subsequence
#1584 Min Cost to Connect All Points

B.2.3 Hard

#23 Merge k Sorted Lists
#72 Edit Distance
#295 Find Median from Data Stream
#315 Count of Smaller Numbers After Self
#787 Cheapest Flights Within K Stops

B.3 Where to find my submissions

Most of the problems above I have submitted multiple times over the years. Solutions live in ~/leetcode-submissions/ organized by problem slug. Filenames are timestamped, so the latest file is usually the cleanest. Older ones often show the evolution — first attempt, optimized version, alternative approach.