Science, Mathematics, Board Games, Hex, Algorithms.
vertex, C2), are in the O- and O’-regions, respectively. Therefore, there is a connecting chain of O- pieces from O to O’⟹ O wins. Note that cases 1 and 2 cannot both occur, as that would imply the tour starting at u forks at some point, which is impossible. Since either case 1 or case 2 must