- 19 Jan, 2026
Dynamic Programming: Patterns & Optimization
Week 26, the finale. A tour of the DP families that cover most interview questions (knapsack, subsequences, grids, intervals), plus rolling-array space optimization.
- 12 Jan, 2026
Backtracking: Permutations, Combinations & Pruning
Week 25 notes: turning the Week 17 template into a toolkit. The three shapes (subsets, combinations, permutations), handling duplicates without dupes, and the pruning that keeps it feasible.
- 05 Jan, 2026
Graphs: Shortest Paths & Dijkstra
Week 24 notes: once edges have weights, plain BFS isn't enough. Picking between BFS, 0-1 BFS, Dijkstra, and Bellman-Ford, plus topological sort for dependency ordering.
- 29 Dec, 2025
Advanced Heap & Priority Queue
Week 23 notes: heaps at interview-hard level. The two-heap running median, k-way merge, greedy scheduling with a priority queue, and the lazy-deletion trick for removing stale entries.
- 22 Dec, 2025
Advanced Binary Tree & BST
Week 22 notes: the harder tree problems, where a node has to report several facts to its parent at once. The return-tuple DFS pattern, lowest common ancestor, path sums, and serialize/deserialize.