Black Out

When you’ve finished solving all problems in this contest, there’s no need to get bored, be- cause we introduce a new and fun game called Black Out! Grab a piece of paper and draw a table of 5 by 6 squares. Next, choose your favorite teammate to play against. Each player in turn selects one or more squares that are adjacent and in the same row or column, and colors them all black. Some of these squares may be black already, but at least one of them must not be. The winner is the player to color the last square(s) black.

Once you got the hang of it, you might want to try and write your own AI player. You can then submit it and let it play a few games against our (= the jury’s) player!

After a lengthy analysis, we have managed to prove that the game is theoretically won by the player who starts, so we’ll gracefully let your player have the first move every time. If you manage to beat our player in every game, you’ll be awarded another point in this contest. But be careful: the jury’s player is not to be underestimated and will surely grab any chance it is offered! If you lose, you’ll get a Wrong Answer. Also note that we are not that patient, so make sure your player is quick to move.

\includegraphics[width=0.3\textwidth ]{blackout}
Figure 1: The move 2 6 5 6 as given in the sample makes all squares from $(2,6)$ to $(5,6)$ black. The squares $(3,6)$ and $(4,6)$ were black already.

Input and Output

This is a problem with interactive input and output, read the following description very carefully.

The first line of the input contains one positive number: the number of games, at most 100. Then, for each game:

  • Your program writes a move on a single line to standard output. A move consists of four space-separated integers $r_1$, $c_1$, $r_2$ and $c_2$ ($1 \le r1 \le r2 \le 5$ and $1 \le c1 \le c2 \le 6$; also, $r1 = r2$ and/or $c1 = c2$) on a single line: the row and column number of the two squares between which all squares are colored black (including the two indicated squares). In case only one square is colored black, $r1 = r2$ and $c1 = c2$.

  • After each move, our program writes one of the following two responses on a single line to standard input:

    • The word “MOVE”, followed by a single space, followed by four space-separated integers, representing the response of our program. Your program must now make another move.

    • The word “GAME”, indicating that the game has ended: either your program has won, or our program intends to make a move that ends the game in its favor.


  • Make sure to print a newline after your move.

C Users

  • Do setlinebuf(stdout); at the start of your program to make sure output is flushed correctly.

  • If you use scanf to read the moves (which we recommend), then do not read the newline character at the end. So, to read the input with scanf, use scanf("%s",s) and scanf("%d %d %d %d", &r1, &c1, &r2, &c2);.
    Also, do not use scanf("MOVE") or scanf("GAME").

C++ Users

  • Recommendation: use std::cin and std::cout to read input and write output. This will ensure output is flushed correctly.

Java users

  • Do not use buffered output; System.out.println will do fine.

Sample Interaction


  • This example is merely to illustrate the communication between your program and the jury’s program; it does not demonstrate an example of optimal play for either player.

  • The extra newlines in the example below are for clarity only, to demonstrate the order of events; you should print exactly one newline character after each move, and the input contains no blank lines either.

Sample Input 1 Sample Output 1

MOVE 3 6 3 6

MOVE 4 2 4 6

MOVE 2 6 5 6

MOVE 3 1 5 1

MOVE 5 2 5 5

2 1 2 4

1 3 5 3

4 1 4 6

1 1 1 6

3 2 3 5

2 5 2 5
CPU Time limit 3 seconds
Memory limit 1024 MB
Difficulty 3.6medium
Statistics Show
License Creative Commons License (cc by-sa)

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