day4.clj

(ns aoc2018.day4
  (:require [clojure.math.combinatorics :as combo]))

(defn add-guard-sleep-time
  [guards-map current-guard last-sleep-time line]
  (let [
        wake-up-time (first (drop 1 (re-find #"\d+-\d+-\d+ \d+:(\d+)" line)))
        nwake-up-time (Integer/parseInt wake-up-time)
        nsleep-time (Integer/parseInt last-sleep-time)]

    (assoc
     guards-map
     current-guard
     (concat (get guards-map current-guard []) (vec (for [x (range nsleep-time nwake-up-time)] x))))))

(defn create-data
  [[guards-map current-guard last-sleep-time] line]
  (cond
    (re-find #"begins shift" line) [guards-map (first (drop 1 (re-find #"Guard #(\d+)" line))) 0]
    (re-find #"falls asleep" line) [guards-map current-guard (first (drop 1 (re-find #"\d+-\d+-\d+ \d+:(\d+)" line)))]
    (re-find #"wakes up" line) [(add-guard-sleep-time guards-map current-guard last-sleep-time line) current-guard 0]))

(defn most-sleepy-guard
  [guardsmap]
  (apply max-key #(count (get guardsmap %)) (keys guardsmap)))

(defn most-slept-minute
  [guardsmap guard]
  (first (last (sort-by val (frequencies (get guardsmap guard))))))

(defn most-slept-minute2
  [guardsmap guard]
  (last (last (sort-by val (frequencies (get guardsmap guard))))))
  
(defn part1
  []
  (with-open [rdr (clojure.java.io/reader "./inputs/day4.txt")]
    (let [lines (line-seq rdr)
          data (reduce
                create-data
                [{} 0 0]
                (sort lines))
          [guardsmap _ _] data
          guard (most-sleepy-guard guardsmap)
          minute (most-slept-minute guardsmap guard)]
      
      
      (println guard)
      (println minute)
      (println (* (Integer/parseInt guard) minute)))))

(defn most-frequent
  [v]
  (first (sort-by val (frequencies v))))

(defn part2
  []
  (with-open [rdr (clojure.java.io/reader "./inputs/day4.txt")]
    (let [lines (line-seq rdr)
          data (reduce
                create-data
                [{} 0 0]
                (sort lines))
          [guardsmap _ _] data
          guard-ids (keys guardsmap)
          guard (apply max-key (partial most-slept-minute2 guardsmap) guard-ids)
          minute (most-slept-minute guardsmap guard)
          ]

      (println (* minute (Integer/parseInt guard))))))


(part2)