cycle-crossover.clj

(map cycle-crossover (pair population))

(defn pair [vec]
  "splits a 1d array into a 2d array of pairs"
  (mapv (fn [i] (subvec vec i (+ 2 i)))
        (map #(* 2 %)
             (range (/ (count vec) 2)))))

(defn cycle-crossover [[a b]]
  "returns both permuations of the parents'
   cycle crossover (changed ordering)"
  (let [cycles (find-all-cycles a b)
        c1     (make-child [a b] cycles)
        c2     (make-child [b a] cycles)]
    [c1 c2]))

(defn make-child [parents cycles]
  "combines parents using cycle crossover"
  (loop [res (vec (repeat 10 nil))
         idx 0]
    (if (= idx (count cycles))
        res
        (recur (reduce (fn [v e] (assoc v (first e) (last e)))
                       res
                       (map (fn [i] [(.indexOf (nth parents (mod idx 2)) i) i])
                            (nth cycles idx)))
               (inc idx)))))