Rolling Hash
5 problems · 4 with full explanations
2 Easy1 Medium1 Hard
Rolling hash computes a new hash from the previous one in O(1) by removing the outgoing character and adding the incoming one. Used in Rabin-Karp string matching and detecting duplicate substrings. Choose a large prime modulus and base to minimize collisions.
How to practice
To practice Rolling Hash problems effectively, start with the Easy problems listed below, trace through each solution on paper, then re-implement without looking. When you can recognise the rolling hash pattern within 30 seconds of reading a new problem, move on to Medium difficulty. Use the related topic pages and our study guide for a structured progression.