Latin Squares

The applet below offers you two problems: one simple and one less simple. In the simple one, you are requested to arrange numbers in a square matrix so as to have every number just once in every row and every column. The second problem imposes one additional condition: the arrangement must be symmetric with respect to the main diagonal (the one from the North-West to the South-East corner.)

There are two ways to manipulate rows of the matrix:

1. You can cycle rows left or right by clicking just outside the matrix
2. You can swap two squares in the same row by clicking first on one and then the other

Remarks