dsa2 min read
Longest Duplicate Substring [Hard] — Binary Search + Rolling Hash
Find the longest substring that appears at least twice using binary search on length and Rabin-Karp rolling hash for O(n log n) average time.
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Rolling-hash
5 articles
dsa1 min read
Repeated DNA Sequences — Rolling Hash
Find all 10-letter DNA sequences that appear more than once. Use rolling hash (4-bit per char) or set of seen substrings.
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dsa2 min read
String Algorithms — Complete Guide (KMP, Z, Rolling Hash, Suffix Array)
Master advanced string algorithms: KMP failure function for O(n) pattern matching, Z-algorithm for all prefix matches, Rabin-Karp rolling hash, and suffix arrays for substring queries.
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dsa2 min read
Rabin-Karp — Rolling Hash for Pattern Matching and Substring Search
Rabin-Karp uses a rolling polynomial hash to match patterns in O(n+m) expected time. The key is updating the hash in O(1) as the window slides.
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dsa2 min read
String Algorithms — Master Recap and Pattern Cheatsheet
Complete recap of all 20 string algorithm problems: pattern recognition guide, algorithm selection, and complexity reference.
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