Problem
1. Describe how you would do external selection: find the kth largest element in a file of N elements, where N is much too large for the file to fit in main memory.
2. Implement the replacement selection algorithm, then use it to test the claim that the runs produced are about twice the internal memory size.
3. What is the worst that can happen when replacement selection is used to pro-duce initial runs in a file of N records, using a priority queue of size M with M < n?>