Cache Query Handler

Problem Overview

• Build a cache query handler that returns the stored value for a given key and timestamp.
• Input: cache_entries (n x 3: timestamp, key, value) and queries (q x 2: key, timestamp); Output: array of q values, all pairs guaranteed present.
• Constraints: n,q ≤ 1e5; timestamps hh:mm:ss; keys lowercase alphanumeric; no duplicate keys at the same time.
• Real-world domain: cache lookup in data systems; a problem and interview question for a coding interview, asked in Ibm interviews.