print traces of graph.

ramen.clj

(use 'clojure.set)
(def middle-cols 5)
(def max-col (inc middle-cols))
(def max-row 2)


(defn row [point] (first point))

(defn col [point] (second point))

(defn valid-row? [point]
  (if (and (>= (row point) 0)
           (<= (row point) max-row))
    true
    false))

(defn valid-col? [point]
  (if (and (>= (col point) 1)
           (<= (col point) max-col))
    true
    false))

(defn new-points-sub [point]
  (let [r (row point)
        c (col point)]
    (set (list [(dec r) c] [(inc r) c] [r (dec c)] [r (inc c)]))))

(defn new-points
  [point]
  (filter #(if (and (valid-row? %) (valid-col? %)) true false) 
          (new-points-sub point)))

(defn new-points-with-trace [point trace]
  (difference (set (new-points point)) (set trace)))

(defn start? [point] (if (<= (col point) 0) true false))

(defn goal? [point] (if (>= (col point) max-col) true false))

(defn ramens-sub [trace]
  (doseq [t (map #(cons % trace) (new-points-with-trace (first trace) (rest trace)))]
    (if (goal? (first t)) (println t)
        (ramens-sub t))))

; print all valid traces
(do (ramens-sub '([0 1]))
    (ramens-sub '([1 1]))
    (ramens-sub '([2 1])))