Track a stream of numbers and answer running min, max, average, and count queries.
Read a stream of integers and answer queries about the numbers seen so far. Process commands from stdin, one per line.
Commands:
- ADD <n> : record the integer n.
- MIN : print the smallest number recorded so far, or "NONE" if none yet.
- MAX : print the largest number recorded so far, or "NONE" if none yet.
- AVG : print the integer average (sum divided by count, truncated toward zero) of the numbers so far, or "NONE" if none yet.
- COUNT : print how many numbers have been recorded.