- 10 Nov, 2025
Dynamic Programming: An Intro
Week 16 notes: DP is just recursion that never repeats work, and it's way less scary than its reputation. Spotting a DP problem, defining a state, and going top-down or bottom-up.
- 03 Nov, 2025
Sorting & Searching Essentials
Week 15 notes: I rarely write a sort from scratch in an interview, but knowing the trade-offs and the 'sort first, then the problem gets easy' instinct is the real skill.
- 27 Oct, 2025
Graphs 101: BFS & DFS Traversals
Week 14 notes: a tree is just a graph without cycles. Graph representations, DFS and BFS with a visited set, shortest paths on unweighted graphs, and grids as graphs.
- 20 Oct, 2025
N-ary Trees: Traversal & Encoding
Week 13 notes: once a node can have any number of children, the binary-tree patterns still work, you just loop over children. Plus encoding an N-ary tree as a binary one.
- 13 Oct, 2025
Tries: Prefix Trees for Fast Lookups
Week 12 notes: a trie stores strings by shared prefixes, so lookup and prefix search depend on word length, not how many words you've got. Where autocomplete comes from.