# language:

python. you can already see from the repo, but this was a laborious choice coupled with my unique circumstance and future goals. GPT5 deeply researched the matter for 7 minutes.

pros:
- syntax is easy
    - harder to bonk in interviews
- easy access to data structures, unlike typescript
- relates well to my longer term Machine Learning Engineer goals

# problems:

## arrays

- [X] 169. Majority Element
- [X] 238. Product of Array Except Self
- [X] 41. First Missing Positive

## strings

- [X] 392. Is Subsequence
- [X] 151. Reverse Words in a String

## bit manipulation

- [X] 338. Counting Bits
- [X] 260. Single Number III

## hash tables

- [X] 49. Group Anagrams
- [X] 128. Longest Consecutive Sequence

## two pointers

- [X] 11. Container With Most Water
- [X] 15. 3Sum
- [X] 01. 2Sum
- [X] 169. Two Sum II
- [ ] 3Sum Smaller
- [ ] 3Sum Closest
- [ ] 42. Trapping Rain Water

## prefix sum

- [ ] 325. Subarray Sum Equals K


## sliding window - fixed size

- [ ] 438. Find All Anagrams in a String
- [ ] 567. Permutation in String

## sliding window - dynamic size

- [ ] 3. Longest Substring Without Repeating Characters
- [ ] 76. Minimum Window Substring


## kadane's algorithm

- [ ] 53. Maximum Subarray

## matrix (2d array)

- [ ] 54. Spiral Matrix
- [ ] 48. Rotate Image


## linked list

- [ ] 19. Remove Nth Node From End of List
- [ ] 24. Swap Nodes in Pairs
- [X] 2. Add Two Numbers

## linked list (in place reversal)

- [ ] 25. Reverse Nodes in k-Group

## fast and slow pointers 

- [ ] 142. Linked List Cycle II


## stacks

- [ ] 20. Valid Parentheses
- [ ] 155. Min Stack


## monotonic stack

- [ ] 84. Largest Rectangle in Histogram


## monotonic queue

- [ ] 239. Sliding Window Maximum


## quicksort / quickselect

- [ ] 75. Sort Colors


## binary search

- [ ] 34. Find First and Last Position of Element in Sorted Array
- [ ] 33. Search in Rotated Sorted Array
- [ ] 4. Median of Two Sorted Arrays


## backtracking

- [ ] 46. Permutations
- [ ] 78. Subsets


## tree traversal (level-order)

- [ ] 102. Binary Tree Level Order Traversal
- [ ] 199. Binary Tree Right Side View


## tree traversal (pre-order)

- [ ] 144. Binary Tree Preorder Traversal
- [ ] 437. Path Sum III
- [ ] 297. Serialize and Deserialize Binary Tree

## tree traversal (in-order)

- [ ] 94. Binary Tree Inorder Traversal
- [ ] 98. Validate Binary Search Tree
- [ ] 230. Kth Smallest Element in a BST

## tree traversal (post-order)

- [ ] 145. Binary Tree Postorder Traversal
- [ ] 236. Lowest Common Ancestor of a Binary Tree
- [ ] 124. Binary Tree Maximum Path Sum

## BST / ordered set

- [ ] 729. My Calendar I

## tries

- [ ] 1804. Implement Trie (Prefix Tree)
- [ ] 212. Word Search II

## two heaps
- [ ] 295. Find Median from Data Stream


## top k elements
- [ ] 347. Top K Frequent Elements


## intervals
- [ ] 56. Merge Intervals
- [ ] 435. Non-overlapping Intervals


## k-way merge
- [ ] 23. Merge k Sorted Lists


## data structure design
- [ ] 146. LRU Cache


## greedy 
- [ ] 45. Jump Game II


## depth first search (dfs)
- [ ] 200. Number of Islands
- [ ] 133. Clone Graph
- [ ] 785. Is Graph Bipartite?


## breadth first search (bfs)
- [ ] 994. Rotting Oranges
- [ ] 127. Word Ladder


## topological sort
- [ ] 210. Course Schedule II


## union find
- [ ] 547. Number of Provinces

## minimum spanning tree (mst)
- [ ] 1584. Min Cost to Connect All Points


## shortest path 
- [ ] 787. Cheapest Flights Within K Stops


## 1-d dynamic programming (dp)

- [ ] 213. House Robber II

## knapsack dynamic programming (dp)

- [ ] 416. Partition Equal Subset Sum

## unbounded knapsack dp

- [ ] 322. Coin Change

## longest increasing subsequence (dp)

- [ ] 300. Longest Increasing Subsequence

## 2d (grid) DP

- [ ] 64. Minimum Path Sum
- [ ] 329. Longest Increasing Path in a Matrix

## string dp

- [ ] 1143. Longest Common Subsequence
- [ ] 139. Word Break

## maths / geometry

- [ ] 7. Reverse Integer
- [ ] 149. Max Points on a Line