Czech ACM Student Chapter
Czech Technical University in Prague
Charles University in Prague
Technical University of Ostrava
acm
ˇ a
Slovak University of Technology
Pavol Jozef Saf´rik University in Koˇice
s
cz
ˇ
University of Zilina
Masaryk University
Matej Bel University in Bansk´ Bystrica
a
University of West Bohemia
CTU Open Contest 2018
Die
die.c, die.cpp, die.c11, Die.java, die.py
The boss of Binary Casino wants to have control over games played in his casino. This is
especially true in the case of dice games, as from time to time people try to cheat their way to
the victory by manipulating dice even after a throw has already occurred. Therefore, there is a
camera installed to monitor the course of every single dice game. Dice recognition, however, is
not an easy task and sometimes a camera may produce a faulty image which makes the task of
recognition impossible.
There are rasterized data available from a camera which took pictures of several dice. The task
is to write a program which determines the value of the top side of the die in the picture or
detects that the picture is corrupted. Note that the picture is transformed in such way that the
sides incident to the captured top side of the die are parallel to the x and y axis. However, it is
unknown which of the four possible rotations of the top side is depicted.
Input Specification
The input specifies the top side of a captured die. It consists of three lines, each with three
characters "o" or ":" representing a dent or a smooth surface, respectively.
Output Specification
Output a single line with either the number represented by the captured top side of the die or
"unknown" if the image is incorrect.
Sample Input 1
Output for Sample Input 1
o:o
5
:o:
o:o
Output for Sample Input 2
Sample Input 2
3
::o
:o:
o::
Sample Input 3
Output for Sample Input 3
ooo
unknown
:::
o:o
