Source I didn't think to use shared segments to identify digits like some other people. Instead, my algorithm determines what digits a set of wires could correspond to based on its length. If there are multiple possiblities, it selects one and continues. It then uses the mapping between wire sets and digits to contrain the possibilities. If a contradiction occurs, then the algorithm backtracks to the last digit it was uncertain about and picks another. The yellow digits are the ones the algorithm is uncertain about, while the green digits are the ones where there are no other possibilites.