Removing Reverse Rows in a Permutation Matrix in Matlab

I'm looking for a quick way in Matlab to do the following:

Given a permutation matrix of a vector, say [1 2 3], I would like to remove all duplicate reverse rows.

So the matrix P=perms([1 2 3])

3 2 1

3 1 2

2 3 1

2 1 3

1 3 2

1 2 3

becomes

3 2 1

3 1 2

2 3 1

Answer 1

[KALYAN ACHARJYA]

P=perms([1 2 3]);
result=P(unique(P(:,2)),:)

result =

     3     2     1
     3     1     2
     2     3     1