#119

Win at Tic-Tac-Toe

 

As in Problem 73, a tic-tac-toe board is represented by a two dimensional vector. X is represented by :x, O is represented by :o, and empty is represented by :e. Create a function that accepts a game piece and board as arguments, and returns a set (possibly empty) of all valid board placements of the game piece which would result in an immediate win. Board coordinates should be as in calls to get-in. For example, [0 1] is the topmost row, center position.

	(= (__ :x [[:o :e :e] [:o :x :o] [:x :x :e]]) #{[2 2] [0 1] [0 2]})
	(= (__ :x [[:x :o :o] [:x :x :e] [:e :o :e]]) #{[2 2] [1 2] [2 0]})
	(= (__ :x [[:x :e :x] [:o :x :o] [:e :o :e]]) #{[2 2] [0 1] [2 0]})
	(= (__ :x [[:x :x :o] [:e :e :e] [:e :e :e]]) #{})
	(= (__ :o [[:x :x :o] [:o :e :o] [:x :e :e]]) #{[2 2] [1 1]})