AlgoSolveoRoadmap › Stage 9: Greedy & Dynamic Programming › Pattern 44 of 53
DSA pattern guide
DP — 2D Grid
Count paths or minimise cost moving through a grid.
Use it when
Count paths or minimise cost moving through a grid.
Key idea
dp[r][c] comes from top/left (or below). Fill row by row, and keep one row to save space.
Practice problems, in order
- Unique PathsMedium
- Unique Paths IIMedium
- Minimum Path SumMedium
- Minimum Falling Path SumMedium
- Dungeon GameHard
- Cherry PickupHard
How to practise this pattern
- Read the problem and look for the signal above before writing any code.
- Say the brute force out loud, with its time complexity, then ask what work it repeats.
- Apply the key idea and write the optimised version yourself.
- If you're stuck for more than 10 minutes, take one small hint, not the full solution.
- Move to the next problem only when you can explain why this pattern fits.
Stuck on one of these?
The AlgoSolveo extension (free, launching soon) sits beside the LeetCode problem and gives the smallest hint that gets you moving, never the full answer. Solved problems tick off on your roadmap.
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