Role classification

Simulate a server of a role-playing game for two players. Each player has an “elo”, which is a value larger the better is the player. Everyone starts with 1200 points, and nobody ever gets a lower quantity, no matter how many games are lost. Whenever there is a match, the winner gets 10 elo points, and the loser loses 10 elo points (with the limitation above). The elo of a player is kept when he or she disconnects from the server.

We have these instructions:

“LOGIN” $j$ : The player $j$ starts a session. Ignore it if the player is already connected.
“LOGOUT” $j$ : The player $j$ closes the session. Ignore it if the player is not connected.
“PLAY” $j_1 \enspace j_2$ : Indicates that $j_1$ has beaten $j_2$ , with $j_1 \ne j_2$ . Ignore it but print an error message if any of the two players is not connected.
“GET_ELO” $j$ : Print the player $j$ (who was connected for sure previously, although now may be disconnected) with his or her current elo.

Input

Input consists of several instructions for at most $10^5$ players. Each player’s name is different and made up of only lowercase letters.

Output

For every instruction “GET_ELO” (and perhaps “PLAY”) print the proper output. At the end, print an empty line, the word “RANKING”, and a ranking sorted in decreasing order by elo (if there is a tie, print first the alfabetically smallest name) with all the players ever connected to the server.

Problem information

Author: Unknown
Translator: Salvador Roura

Generation: 2026-01-25T11:05:45.497Z