repeated elements in matrix

i have a Nx4 matrix like this [1 2 3 1; 2 1 3 2; 3 2 1 3] with the values of nodes making a clique, i need to find the occurances of a 1x2 matrix for instance [1 2] any suggestions?

[Joseph Cheng]

for your example of [1 2] is that different from [1;2] [2;1] or [2 1]? or are these separate instances?

[Charis L]

it is like the first row of the first matrix consists of [1 2] [2 3] [3 1] also i only need row comparison and not column(and [1 2] is different from [2 1].