A standard and diagonal Sudoku were solved using integer programming with binary variables in a feasibility problem.
The programming language used was MATLAB, including its solver.
A report about the project was made in Portuguese, while the English one is being done (including the comments in the routines). Take a look at "Sudoku_report".
Reference: https://www.mathworks.com/help/optim/ug/sudoku-puzzles-problem-based.html