MathDB
Problems
Contests
National and Regional Contests
Japan Contests
Japan TST
2021 Japan TST
8
8
Part of
2021 Japan TST
Problems
(1)
An international conference
Source: 2021 Japan TST, P8
10/30/2021
Let
n
n
n
be an integer greater than or equal to
2
2
2
.
n
n
n
people from each of
n
n
n
countries gather, a total of
n
2
n^2
n
2
people facing inward and surround the round table. For any two different people in the same country, their left neighbors belong to different countries. Find the maximum number of people whose left and right neighbors belong to the same country.
combinatorics