Sorting 1 million 8-decimal-digit numbers with 1 MB of RAM

Question

I have a computer with 1 MB of RAM and no other local storage. I must use it to accept 1 million 8-digit decimal numbers over a TCP connection, sort them, and then send the

Answer 1

I would exploit the retransmission behaviour of TCP.

1. Make the TCP component create a large receive window.
2. Receive some amount of packets without sending an ACK for them.
   • Process those in passes creating some (prefix) compressed data structure
   • Send duplicate ack for last packet that is not needed anymore/wait for retransmission timeout
   • Goto 2
3. All packets were accepted

This assumes some kind of benefit of buckets or multiple passes.

Probably by sorting the batches/buckets and merging them. -> radix trees

Use this technique to accept and sort the first 80% then read the last 20%, verify that the last 20% do not contain numbers that would land in the first 20% of the lowest numbers. Then send the 20% lowest numbers, remove from memory, accept the remaining 20% of new numbers and merge.**