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C7
C7
Part of
2021-IMOC
Problems
(1)
Tiling the plane with (n)guns
Source: IMOC 2021 C7
8/11/2021
Given a positive integer
n
n
n
, an
n
n
n
-gun is a
2
n
2n
2
n
-mino that is formed by putting a
1
×
n
1 \times n
1
×
n
grid and an
n
×
1
n \times 1
n
×
1
grid side by side so that one of the corner unit squares of the first grid is next to one of the corner unit squares of the second grid. Find the minimum possible
k
k
k
such that it is possible to color the infinite planar grid with
k
k
k
colors such that any
n
n
n
-gun cannot cover two different squares with the same color.Itf0501
combinatorics
Tiling