In CS101 our final was to build a sudoku solver in C++. I think the best student time was a minute. At the end of the semester I went to the professor’s office

In CS101 our final was to build a sudoku solver in C++. I think the best student time was a minute. At the end of the semester I went to the professor’s office to ask about optimizations that could’ve been made and he showed me a bash one-liner that solved a sudoku in under a second. I wish I remembered what the one liner was!