For each formulation problem, please define your decision variables clearly. You need to submit your code for solutions.

A game board consists of nine equal squares. You are required to fill each square with a

number between 1 and 9 such that the sum of the numbers in each row and each column

equals 15. Determine the number in each square for the following cases:

a) No two adjacent numbers in any row or any column are equal.

b) The numbers in all the squares are distinct.