Question: Write a Prolog program to solve the 6 by 6 Sudoku puzzle distributed in class. Do not use a solution downloaded from the Internet or elsewhere. Write your own. It should be designed along these lines: Label the squares X1, X2, ..., X36 as discussed in class. The X1,..., X36 represent the 36 squares in the Sudoku puzzle (row by row). Set the known values of the X's and then generate needed permutations and test for compliance with problem constraints. Your query should be
sudoku (X1,X2,X3,X4,X5,X6,X7,X8,X9,X,X11,X12,X13,X14, X15,X16,X17,X18,X19,X20,X21,X22, X23,X24,X25,X26,X27,X28,X29,X30,X31,X32,X33,X34,X35,X36).
The result will be values for X1, ... , X36 that solve the problem. Find all possible solutions. Your program should be general, in the sense that it could be easily modified to handle another 6 by 6 Sudoku problem.
Your program should run in less than a 2 minutes. If it takes a "long time" try to speed it by checking more constraints earlier in the program. You should be able to get your program to run is less than a minute.