Match substrings without inventing matches
Repair collection behavior, then find containing words with careful identity, boundary, and performance checks.
What you will practice
- Translate the exact word-identity contract into tests.
- Distinguish a substring from a subsequence or prefix.
- Compare indexing work with repeated scans.
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Sources and scope
The cited employer material supports the preparation format and skills, not these exact tasks, APIs, tests, or timings. Existing nrml exercises retain their own provenance. Reading times and rehearsal budgets are nrml suggestions. Completion records practice and review, not hiring readiness.
- Meta hiring FAQ · practical-format context, not attribution of this exerciseReviewed 2026-10-28