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Cono Sur Olympiad
1997 Cono Sur Olympiad
4
4
Part of
1997 Cono Sur Olympiad
Problems
(1)
A construction of a board
Source: Cono Sur 1997, Problem 4
5/11/2018
Consider a board with
n
n
n
rows and
4
4
4
columns. In the first line are written
4
4
4
zeros (one in each house). Next, each line is then obtained from the previous line by performing the following operation: one of the houses, (that you can choose), is maintained as in the previous line; the other three are changed: * if in the previous line there was a
0
0
0
, then in the down square
1
1
1
is placed; * if in the previous line there was a
1
1
1
, then in the down square
2
2
2
is placed; * if in the previous line there was a
2
2
2
, then in the down square
0
0
0
is placed; Build the largest possible board with all its distinct lines and demonstrate that it is impossible to build a larger board.
cono sur
combinatorics