MathDB
Problems
Contests
Undergraduate contests
Putnam
1996 Putnam
3
Putnam 1996 B3
Putnam 1996 B3
Source:
June 6, 2014
Putnam
college contests
Problem Statement
Let
S
n
S_n
S
n
be the set of all permutations of
(
1
,
2
,
…
,
n
)
(1,2,\ldots,n)
(
1
,
2
,
…
,
n
)
. Then find :
max
σ
∈
S
n
(
∑
i
=
1
n
σ
(
i
)
σ
(
i
+
1
)
)
\max_{\sigma \in S_n} \left(\sum_{i=1}^{n} \sigma(i)\sigma(i+1)\right)
σ
∈
S
n
max
(
i
=
1
∑
n
σ
(
i
)
σ
(
i
+
1
)
)
where
σ
(
n
+
1
)
=
σ
(
1
)
\sigma(n+1)=\sigma(1)
σ
(
n
+
1
)
=
σ
(
1
)
.
Back to Problems
View on AoPS