Sha256: f375e396374d00b79f302e18b7677d53dac1dc562168892651f853c73ffae39b
Contents?: true
Size: 572 Bytes
Versions: 39
Compression:
Stored size: 572 Bytes
Contents
(ns dominoes)
(defn rm [xs x]
(let [i (.indexOf xs x)]
(if (= -1 i) xs (vec (concat (take i xs) (drop (inc i) xs))))))
(defn connects [[a b] [c d]]
(cond (= b c) [c d]
(= b d) [d c]
:else nil))
(defn backtrack [rem chain]
(or (and (empty? rem) (= (ffirst chain) (second (peek chain))))
(and (not (empty? rem))
(some #(let [c (connects (peek chain) %)]
(and c (backtrack (rm rem %) (conj chain c))))
rem))))
(defn can-chain? [xs]
(or (empty? xs) (some #(backtrack (rm xs %) [%]) xs)))
Version data entries
39 entries across 39 versions & 1 rubygems