connected.clj

(defn node [g]
  (set (flatten g)))

(defn adjList [g]
   (into {} (vec ((fn [m] into {} (for [[k v]m] {k (node v)}))(group-by first g)))))

(defn connected? [g a b]
  (loop [n (a g)
         v #{}]
    (let [diff (clojure.set/difference  n v)]
      (if (clojure.set/superset? v n) false
       (if (contains? n b) true
            (recur
              (flatten (into #{} (vec (map #(replace {% (% g)} n) n))))
              ;;(into #{} (vec ((fn [m] into {}(for [x m](x g)))n)))
            (set (concat n v))))))))