array plus enumeration Pattern
9 problems
Pattern pages help build reusable solving frames. Identify signals first, then explain state, transition, and edge handling.
Recognition Signals
- Asks if brute-force enumeration is acceptable given small constraints.
- Checks understanding of absolute difference and triplet conditions.
- Looking for awareness of pattern repetition and consecutive subarray detection.
Solve Flow
- 1. Define the active state/window.
- 2. Update state while preserving invariants.
- 3. Validate with edge-heavy examples.
Common Misses
- Using <= instead of < for indices, causing duplicates or invalid triplets.
- Not verifying consecutive repetitions correctly, leading to false positives.
- Forgetting the radius cutoff, leading to including towers beyond reach.
Recommended Ladder
Count Good Triplets
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Detect Pattern of Length M Repeated K or More Times
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Collecting Chocolates
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Longest Alternating Subarray
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Sum of Squares of Special Elements
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Minimum Operations to Maximize Last Elements in Arrays
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Find the Peaks
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Maximum Height of a Triangle
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