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leetwinski/advent_2020_15.clj

Last active December 24, 2020 10:49
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Revisions

  1. leetwinski revised this gist Dec 24, 2020. 1 changed file with 10 additions and 12 deletions.
    22 changes: 10 additions & 12 deletions advent_2020_15.clj
    View file
    Original file line number Diff line number Diff line change
    @@ -7,18 +7,16 @@
    [(inc i)
    (- i (data n i))]])

    (defn nth-num [seed n]
    (->> [(into {} (map vector (butlast seed) (range)))
    [(dec (count seed)) (last seed)]]
    (iterate next-num)
    (map second)
    (drop-while #(< (first %) (dec n)))
    first))

    ;; part 1
    (->> [(into {} (map vector (butlast seed) (range)))
    [(dec (count seed)) (last seed)]]
    (iterate next-num)
    (map second)
    (drop-while #(< (first %) 2019))
    first)
    (nth-num seed 2020)

    ;; part 2
    (->> [(into {} (map vector (butlast seed) (range)))
    [(dec (count seed)) (last seed)]]
    (iterate next-num)
    (map second)
    (drop-while #(< (first %) 29999999))
    first)
    (nth-num seed 30000000)
  2. leetwinski created this gist Dec 24, 2020.
    24 changes: 24 additions & 0 deletions advent_2020_15.clj
    View file
    Original file line number Diff line number Diff line change
    @@ -0,0 +1,24 @@
    (ns advent-2020-15)

    (def seed [1,2,16,19,18,0])

    (defn next-num [[data [i n]]]
    [(assoc data n i)
    [(inc i)
    (- i (data n i))]])

    ;; part 1
    (->> [(into {} (map vector (butlast seed) (range)))
    [(dec (count seed)) (last seed)]]
    (iterate next-num)
    (map second)
    (drop-while #(< (first %) 2019))
    first)

    ;; part 2
    (->> [(into {} (map vector (butlast seed) (range)))
    [(dec (count seed)) (last seed)]]
    (iterate next-num)
    (map second)
    (drop-while #(< (first %) 29999999))
    first)