ariarule-4clojure-solution73.clj

;; ariarule's solution to Analyze a Tic-Tac-Toe Board
;; https://4clojure.com/problem/73

(fn analyze-tic-tac-toe [board]
  (let [things-to-check 
     [{:step (fn [z] [(first z),(inc (second z))])
           :start [[0,0] [1,0] [2,0]]}
       {:step (fn [z] [(inc (first z)),(second z)])
           :start [[0,0] [0,1] [0,2]]}
       {:step (fn [z] [(inc (first z)),(inc (second z))])
           :start [[0,0]]}
       {:step (fn [z] [(inc (first z)),(dec (second z))])
           :start [[0,2]]}]
      pieces #{:x :o}]
    (some pieces (map
      #(if (reduce
        (fn [b3 thing-to-check]
          (or b3 (reduce
            (fn [b2 start]
              (or b2 (reduce
                 (fn [b coord] (let [[x y] coord]
                     (and b (= % (nth (nth board x) y)))))
                 true
                 (take 3 (iterate (thing-to-check :step) start)))))
            false
            (thing-to-check :start))))
        false
        things-to-check)
        %)
      pieces))))