Perform an External Merge Sort with a Heap
Company: Citadel
Role: Software Engineer
Category: Coding & Algorithms
Difficulty: medium
Interview Round: Onsite
Overview: Implement external merge sort by splitting integers into memory-bounded sorted runs and merging them with a deterministic min-heap. Preserve duplicates, validate input, and explain how the in-memory simulation translates to temporary files and buffered readers.
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