- #1

KodRoute

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## Homework Statement

Find the sign of the permutation --> Picture here: http://tinypic.com/view.php?pic=2q8rkso&s=5

No other given data.

## Homework Equations

ε(σ) = (-1)^m(σ).

If i < j and σ(i) > σ(j) then there's an inversion.

Where ε(σ) denotes the sign of the permutation and m(σ) the number of inversions.

## The Attempt at a Solution

What I tried to do is this:

σ(1) = 2n + 1

σ(2) = 2n

2n + 1 > 2n -- yes

Now what? Should I go on doing the same?

I mean, if the permutation belongs directly to S2, S3 or any other number you can count the inversions but how do I count the inversions now?

Thank you.