Comment by irchans
4 days ago
I also wrote a brute force, kinda dumb, depth-first Suduoku solver. I think it took me a few hours in C or C++. At every node in the search tree, I just checked to make sure no constraints were violated. If I remember correctly, it would run in less than 30 seconds and it would always find a solution if a solution existed. (It might have been a lot less than 30 seconds. I only remember thinking, "That was quick".)
I wrote a sudoku solver, that will create 9x9 array of arrays filled with numbers 1-9 for "blank" fields and only the number in defined field. Then for each square with only one number, I removed the number in that square from all arrays in row, column and subsquare. That typically left me with a solved array, but will contain all possible results for "guessing" fields. It was written in php (the thing I leaned at the time) and ran too fast for me to bother measuring, less than a second. Since I've "solved all sudokus" they stopped being fun.
Yep, pretty much the same approach and experience, only mine was in c# as I was learning the language then. "brute force" by definition will find a solution, if it exists.