Advent of Code '19 day 3 part 1

day3part1.clj

(defn step [s]
  [(keyword (subs s 0 1)) (Integer/parseInt (subs s 1))])

(defn get-dots [dots action]
  (let [[op len] action
        dots dots
        from (last dots)
        [from_x from_y] from
        f+x (partial + from_x 1)
        f-x (partial - from_x 1)
        f+y (partial + from_y 1)
        f-y (partial - from_y 1)]
    (case op
      :R (map (fn [x] [(f+x x),from_y])  (range len))
      :L (map (fn [x] [(f-x x),from_y])  (range len))
      :U (map (fn [x] [from_x,(f+y x)])  (range len))
      :D (map (fn [x] [from_x,(f-y x)])  (range len)))))
    
(defn do-step [acc step]
    (into acc (get-dots acc step))  
  )

(let [n3input  (clojure.string/split n3input_str #",")
      n3input2 (clojure.string/split n3input_str_2 #",")
      steps1 (map step n3input)
      steps2 (map step n3input2)
      dots1  (rest (reduce do-step [[0,0]] steps1))
      dots2  (rest (reduce do-step [[0,0]] steps2))
      crosses (clojure.set/intersection (set dots1) (set dots2))
      ]

     (sort-by (fn [[x y]] (+ (Math/abs x) (Math/abs y)) ) crosses)  
  )