Rabin-Karp Deep Dive

Why it matters

Rabin-Karp enables multi-pattern + fingerprinting. Understanding shapes hash-based matching.

The architecture

Rolling hash: h(text[i..i+m]) computed incrementally.

Compare hash first.

Verify on hash match.

How it works end to end

Polynomial rolling hash.

Modular arithmetic prevents overflow.

Verify: O(m) on hash hit.

Multi-pattern: hash set.