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2D DP — Grid & Substring Problems

Unique paths, edit distance, LCS — learn to model 2D state transition tables.

2D DP: state is two indices (i,j). Classic problems: edit distance, LCS, unique paths, grid DP. dp[i][j] usually represents "optimal answer using first i and j items".

2D Dynamic Programming

More in Dynamic Programming

DP Fundamentals
Memoization vs tabulation, overlapping subproblems, and optimal substructure.
1D DP — Fibonacci & Climbing Stairs
Classic linear DP patterns with state as a single value.
0/1 Knapsack & Unbounded Knapsack
The most important DP sub-category — choose items with weight/value constraints.
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1D DP — Fibonacci & Climbing Stairs
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0/1 Knapsack & Unbounded Knapsack