leetcoding

2024-01-18

reference for later, just documenting LC journey as I embark on it again.

Backtracking

It's like DFS but where we track the state as well, I really really liked this Leetcode card.

Problems and why I think they matter:

• picking up the template — letter combinations of a phone number
• word search
• word search II — this one requires an additional structure!
• optimizing pruning strategy — n-queens, combination sum, subsets II

Fundamental Graphs

Super important as this structure is actually used in real life. I sometimes imagine what it would be like to solve one of these for starlink or something haha.

BFS problems:

• walls and gates

Kahn's Algorithm — I really liked this explore card on it and explaining why it's good as a pruning strategy.

• course schedule
• course schedule II

Union Find:

• redundant connection
• graph valid tree

Adjacency Lists:

• word ladder