advanced
12 min read
Longest Valid Parentheses
Counting matching pairs is not enough. The pairs must form one contiguous, well-formed region, and valid regions can nest, touch, or be separated by an…
View solutionintermediate
One-Dimensional Dynamic Programming
Solve problems with one-dimensional DP states, recurrences, base cases, and memory compression.
Problems
Problems in One-Dimensional Dynamic Programming
Practice problems that share this primary solution pattern and compare the clues that reveal it.
beginner
9 min read
Climbing Stairs
The reliable way to solve Climbing Stairs is to stop guessing “Fibonacci” and ask one structural question: what could the final move have been?
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intermediate
11 min read
Decode Ways
The recurrence resembles Fibonacci, but zeros can remove transitions entirely. Derive the valid-token transitions first; the dynamic program then follows…
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intermediate
10 min read
Maximum Subarray
Resetting a running sum to zero looks like the obvious solution—until the array contains only negative numbers. Then the algorithm can quietly return an…
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advanced
11 min read
Unique Binary Search Trees
The shape is what you count; BST ordering is what makes each root split deterministic.
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