sbenhaim · December 18, 2015 16:03
diff --git a/advent-14.clj b/advent-14.clj
 (ns advent.a14
  (:require [clojure.string :as str]))

 (def rules "Rudolph can fly 22 km/s for 8 seconds, but then must rest for 165 seconds.
 Cupid can fly 8 km/s for 17 seconds, but then must rest for 114 seconds.
 Prancer can fly 18 km/s for 6 seconds, but then must rest for 103 seconds.
 Donner can fly 25 km/s for 6 seconds, but then must rest for 145 seconds.
 Dasher can fly 11 km/s for 12 seconds, but then must rest for 125 seconds.
 Comet can fly 21 km/s for 6 seconds, but then must rest for 121 seconds.
 Blitzen can fly 18 km/s for 3 seconds, but then must rest for 50 seconds.
 Vixen can fly 20 km/s for 4 seconds, but then must rest for 75 seconds.
 Dancer can fly 7 km/s for 20 seconds, but then must rest for 119 seconds.")

 (defn parse-int [s]
  (Integer/parseInt s))

 (defn parse [rule]
  (let [[_ vel time rest] (re-find #".*?(\d+) km/s for (\d+) seconds.*?(\d+) seconds." rule)]
    (map parse-int [vel time rest])))

 (defn vel-at-second [[vel time rest]]
  (cycle (concat (repeat time vel) (repeat rest 0))))

 (defn distance-at [time vs]
  (reduce + (take time (vel-at-second vs))))o

 (defn rolling-sum [is]
  (reduce (fn [r i] (conj r (+ (or (last r) 0) i))) [] is))

 (defn transpose [vss]
  (for [i (range (count (first vss)))]
    (for [vs vss]
      (nth vs i))))

 (defn score-race [vss]
  (transpose
   (for [vs (transpose vss)]
     (let [fstst (apply max vs)]
       (for [v vs]
         (if (== v fstst) 1 0))))))

 (let [time 2503]
  (->> (str/split-lines rules)
       (map parse)
       (map vel-at-second)
       (map (partial take time))
       (map rolling-sum)
       score-race
       (map #(reduce + %))
       (apply max)))
	(ns advent.a14
	(:require [clojure.string :as str]))

	(def rules "Rudolph can fly 22 km/s for 8 seconds, but then must rest for 165 seconds.
	Cupid can fly 8 km/s for 17 seconds, but then must rest for 114 seconds.
	Prancer can fly 18 km/s for 6 seconds, but then must rest for 103 seconds.
	Donner can fly 25 km/s for 6 seconds, but then must rest for 145 seconds.
	Dasher can fly 11 km/s for 12 seconds, but then must rest for 125 seconds.
	Comet can fly 21 km/s for 6 seconds, but then must rest for 121 seconds.
	Blitzen can fly 18 km/s for 3 seconds, but then must rest for 50 seconds.
	Vixen can fly 20 km/s for 4 seconds, but then must rest for 75 seconds.
	Dancer can fly 7 km/s for 20 seconds, but then must rest for 119 seconds.")

	(defn parse-int [s]
	(Integer/parseInt s))

	(defn parse [rule]
	(let [[_ vel time rest] (re-find #".?(\d+) km/s for (\d+) seconds.?(\d+) seconds." rule)]
	(map parse-int [vel time rest])))

	(defn vel-at-second [[vel time rest]]
	(cycle (concat (repeat time vel) (repeat rest 0))))

	(defn distance-at [time vs]
	(reduce + (take time (vel-at-second vs))))o

	(defn rolling-sum [is]
	(reduce (fn [r i] (conj r (+ (or (last r) 0) i))) [] is))

	(defn transpose [vss]
	(for [i (range (count (first vss)))]
	(for [vs vss]
	(nth vs i))))

	(defn score-race [vss]
	(transpose
	(for [vs (transpose vss)]
	(let [fstst (apply max vs)]
	(for [v vs]
	(if (== v fstst) 1 0))))))

	(let [time 2503]
	(->> (str/split-lines rules)
	(map parse)
	(map vel-at-second)
	(map (partial take time))
	(map rolling-sum)
	score-race
	(map #(reduce + %))
	(apply max)))