How do you decide whether a string can be segmented into dictionary words?
PICTURE THIS: PYTHON TYPES
Simple meaning
dp[i] is true if some word ends at i-1 and dp[i-len] is true.
WHY — DP instead of guessing?
Why interviewers care about DP:
question about DP.
trade-offs, and what you would actually do on a DSA project - not buzzwords.
Name the idea, why it exists, then one short example.
End with when you use it and one common pitfall.
STEPS — What happens step by step?
Before you speak the answer, walk the interviewer through these steps:
- 1dp[i] is true if
some word ends at i-1 and dp[i-len] is true.
- 2Check O(n) splits, each
against a hash set of words: O(n^2) time with substring hashing, space O(n) plus the dictionary.
- 3How it works
A trie can share prefixes
- 4empty string is true
as the base.
- 5Common mistake
What juniors usually get wrong.
- 6Close
When you pick this over the alternative.
EXAMPLE — See it in action
Here's a short line you can speak, broken into clear beats:
Note: Adapt this scaffold to your own project — keep it under 60–90 seconds.
Key takeaway
dp[i] is true if some word ends at i-1 and dp[i-len] is true. Check O(n) splits, each against a hash set of words: O(n^2) time with substring hashing, space O(n) plus the dictionary.