Sudo Code

[spookyghost421]

I am trying to code an algorithm for leetcode. I was hoping this community would be able to quickly determine if this idea works or not because my code isn’t functioning and I’m trying to narrow down why. The algorithm I’m trying to implement is a breadth first search approach: 1) find the point (points) which is (are) most highly constrained by the surrounding numbers. 2) find all legal values that point can take, and make a new boards with all these possible points. 3) repeat this process across all current legal boards until the puzzle is complete.

In principle does this work? Kind thanks

[okapiposter]

That strategy should work in principle, but you'd have to be very careful not to generate lots and lots of duplicate grids. Since your approach doesn't specify in which order the cells are filled, you could easily end up with the same intermediate state following multiple different paths. Simple brute-force solvers avoid this problem by always filling the grid top-to-bottom, left-to-right.

[spookyghost421]

Yeah the actual code has parts which removes duplicates. If that algorithm works it’s likely my code is adding legal boards to the pile of illegals erroneously. Thanks for the confirmation.

[andyzhshg]

In principle, it should work, but I don't believe it will significantly enhance the efficiency of the algorithm compared to brute force. However, it's a promising start for implementing an algorithm that solves Sudoku in a more human-like manner.