London Clojure User Group - Jan 2012 - Dreadnought

strategy

(defn adjacent? [[x1 y1] [x2 y2]]
          (or
           (and (= x1 x2) (= (Math/abs (- (int y1) (int y2))) 1))
           (and (= y1 y2) (= (Math/abs (- (int x1) (int x2))) 1))
           ))

(defn is-good-move? [hits move]
  (not (empty? (filter (fn [[candidate hit]] (adjacent? candidate hit)) (map vector (repeat move) hits)))))

(defn choices [shots]
  (clojure.set/difference
                 (set (for [row ["A" "B" "C" "D" "E" "F" "G" "H" "I" "J"]
                            column (vec (range 1 11))]
                        (reduce str [row column])))
                 (set shots)))

(defn next-shot
  "Where do you want to attack next?"
  [{:keys [shots hits]} opponent-context]
  (let [moves (choices shots)]
    (or
     (first (filter (partial is-good-move? hits) moves))
     (first moves))))