Word Break: can a string be segmented into dictionary words?

Word Break is the classic 1D string DP that snags people who reach for greedy or naive recursion. What interviewers watch for: the dp[i] = 'is the prefix of length i segmentable' recurrence, plus why a locally valid split can doom the rest. Here is the answer.

Updated Sep 2026 · Grounded in real GenAI, LLM, and AI/ML engineering interview loops and written to a senior-engineer editorial bar.