meetup-2022-05-04.clj

(ns exercises.core
  (:require
    [clojure.walk :as walk]))

;; trie

; "hello"
; "hi"
; "he"

; h
;    e
;      EOW
;      l
;        l
;           o
;             EOW
;    i
;      EOW


(def trie
 {\h {\i {:EOW nil}
      \e {:EOW nil
          \l {\l {\o {:EOW nil}}}}}})


(defn all-words [trie]
  (walk/postwalk (fn [e]
                  (cond
                    (= e nil) [""]
                    (= :EOW e) ""
                    (map? e) (mapcat (fn [[k vs]]
                                      (map (fn [v] (str k v)) vs))
                                     e)
                    :else e))
                 trie))

(defn subtree [trie query]
   (get-in trie query))

#_(map identity "he")

#_(subtree trie "he")

(defn autocomplete [trie query]
  (map (partial str query) (all-words (subtree trie query))))

#_(autocomplete trie "he")

(cons "he" ["" "llo"])


["" "llo"]
["he" "hello"]

(map (partial str "he") ["" "llo"])




(mapcat (fn [[k vs]]
         (map (fn [v] (str k v)) vs))
        {\a ["b" "c"]
         \d ["e" "f"]})

"ab" "ac"
"de" "df"

#_(autocomplete trie "he")
; #{"hello" "he"}


(def words ["hello" "hi" "he"])

(defn trie
  [words]
  (reduce (fn [memo word]
            (assoc-in memo (conj (vec word) :EOW) nil))
          {} words))

#_(assoc-in {} [\a \b \c \d \e] nil)
#_(trie words)