Find the largest k numbers in k arrays stored across k machines

Question

This is an interview question. I have K machines each of which is connected to 1 central machine. Each of the K machines have an array of 4 byte numbers in file. You can use

Answer 1

• Maintain a min heap of size 'k' in the centralized server.
• Initially insert first k elements into the min heap.
• For the remaining elements
  • Check(peek) for the min element in the heap (O(1))
  • If the min element is lesser than the current element, then remove the min element from heap and insert the current element.
• Finally min heap will have 'k' largest elements
• This would require n(log k) time.