Solving a Sudoku game is a combinatorial task of intermediate complexity. The gênerai problem of filling in an incomplète n 2 x n 2 grid with n x n subgrids belongs to the class of NP-complete problems. Thèse problems are conjectured to increase in computational complexity at an exponential rate in n. Nonetheless, a well planned exhaustive search can work quite well for a low value of n such as 9. For larger values of n, brute force, no matter how cleverly executed, is simply not an option. In contrast, simulated annealing and alternating projections may yield good approximate solutions and partially salvage the situation.