RosettaCodeData/Task/Knights-tour/Clojure/knights-tour.clj
2017-09-25 22:28:19 +02:00

25 lines
949 B
Clojure

(defn isin? [x li]
(not= [] (filter #(= x %) li)))
(defn options [movements pmoves n]
(let [x (first (last movements)) y (second (last movements))
op (vec (map #(vector (+ x (first %)) (+ y (second %))) pmoves))
vop (filter #(and (>= (first %) 0) (>= (last %) 0)) op)
vop1 (filter #(and (< (first %) n) (< (last %) n)) vop)]
(vec (filter #(not (isin? % movements)) vop1))))
(defn next-move [movements pmoves n]
(let [op (options movements pmoves n)
sp (map #(vector % (count (options (conj movements %) pmoves n))) op)
m (apply min (map last sp))]
(first (rand-nth (filter #(= m (last %)) sp)))))
(defn jumps [n pos]
(let [movements (vector pos)
pmoves [[1 2] [1 -2] [2 1] [2 -1]
[-1 2] [-1 -2] [-2 -1] [-2 1]]]
(loop [mov movements x 1]
(if (= x (* n n))
mov
(let [np (next-move mov pmoves n)]
(recur (conj mov np) (inc x)))))))