1113 - Double Queue
Time Limit : 1 Second
Memory Limit : 128 MB
Submission: 11
Solved: 4
- Description
-
The new founded Balkan Investment Group Bank (BIG-Bank) opened a new office in
Bucharest, equipped with a modern computing environment provided by IBM Romania, and using
modern information technologies. As usual, each client of the bank is identified by a positive
integer K and, upon arriving to the bank for some services, he or she receives a positive integer
priority P. One of the inventions of the young managers of the bank shocked the software
engineer of the serving system. They proposed to break the tradition by sometimes calling the
serving desk with the lowest priority instead of that with the highest priority. Thus, the system will
receive the following types of request:
0 The system needs to stop serving
1 K P Add client K to the waiting list with priority P
2 Serve the client with the highest priority and drop him or her from the waiting list
3 Serve the client with the lowest priority and drop him or her from the waiting list
Your task is to help the software engineer of the bank by writing a program to implement the
requested serving policy.
- Input
- Each line of the input contains one of the possible requests; only the last line contains the
stop-request (code 0). You may assume that when there is a request to include a new client in
the list (code 1), there is no other request in the list of the same client or with the same priority.
An identifier K is always less than 106
, and a priority P is less than 107
. The client may arrive for
being served multiple times, and each time may obtain a different priority.
- Output
- For each request with code 2 or 3, the program has to print, in a separate line of the standard
output, the identifier of the served client. If the request arrives when the waiting list is empty, then
the program prints zero (0) to the output. - sample input
-
2 1 20 14 1 30 3 2 1 10 99 3 2 2 0
- sample output
-
0 20 30 10 0
- hint
- source
- Southeastern European Regional Programming Contest Bucharest, Romania October 27, 2007