day4

day4/LICENSE

@@ -0,0 +1,30 @@
+Copyright Ilya Bobyr (c) 2018
+
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+    * Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+
+    * Redistributions in binary form must reproduce the above
+      copyright notice, this list of conditions and the following
+      disclaimer in the documentation and/or other materials provided
+      with the distribution.
+
+    * Neither the name of Ilya Bobyr nor the names of other
+      contributors may be used to endorse or promote products derived
+      from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

day4/README.md

@@ -0,0 +1 @@
+# day4

day4/Setup.hs

@@ -0,0 +1,2 @@
+import Distribution.Simple
+main = defaultMain

day4/day4.cabal

@@ -0,0 +1,25 @@
+name:                day4
+version:             0.1.0.0
+-- synopsis:
+-- description:
+homepage:            https://github.com/ilya-bobyr/advent-of-code-2018/day4#readme
+license:             BSD3
+license-file:        LICENSE
+author:              Ilya Bobyr
+maintainer:          [email protected]
+copyright:           (c) 2018 Ilya Bobyr
+category:            Web
+build-type:          Simple
+cabal-version:       >=1.10
+extra-source-files:  README.md
+
+executable day4
+  hs-source-dirs:      src
+  main-is:             Main.hs
+  default-language:    Haskell2010
+  ghc-options:         -O2 -fdiagnostics-color=always
+  build-depends:       base >= 4.7 && < 5
+                     , containers
+                     , parsec
+                     , sort
+                     , time

day4/src/Main.hs

@@ -0,0 +1,152 @@
+{-# LANGUAGE LambdaCase #-}
+
+module Main where
+
+import Prelude hiding (log)
+
+import Data.Bits (setBit, popCount, testBit)
+import Data.List (foldl', maximumBy, elemIndex)
+import Data.Ord (comparing)
+import Data.Map.Strict (Map)
+import qualified Data.Map.Strict as Map
+import Data.Sort (sortOn)
+import Data.Word (Word64)
+import Text.Parsec (parse)
+import Text.Parsec.Prim (try, (<|>))
+import Text.Parsec.Char (char, digit, space, spaces, string, newline)
+import Text.Parsec.Combinator (many1, eof, sepEndBy)
+import Text.Parsec.String (Parser)
+import Text.Printf (printf, perror)
+
+data LogEvent = BeginShift Int
+              | FallAsleep
+              | WakeUp
+  deriving (Show)
+
+data LogDate = LogDate Int Int Int
+  deriving (Eq, Ord)
+
+instance Show LogDate where
+  show (LogDate year month day) = printf "%d-%02d-%02d" year month day
+
+data LogTime = LogTime Int Int
+  deriving (Eq, Ord)
+
+instance Show LogTime where
+  show (LogTime hour minute) = printf "%02d:%02d" hour minute
+
+data LogDateTime = LogDateTime LogDate LogTime
+  deriving (Eq, Ord)
+
+instance Show LogDateTime where
+  show (LogDateTime date time) = show date ++ " " ++ show time
+
+data LogEntry = LogEntry {
+  unLogDateTime :: LogDateTime,
+  unLogEvent :: LogEvent
+}
+  deriving (Show)
+
+logDateTime :: Int -> Int -> Int -> Int -> Int -> LogDateTime
+logDateTime year month day hour minute =
+  LogDateTime (LogDate year month day) (LogTime hour minute)
+
+rowParser :: Parser LogEntry
+rowParser = do
+  _ <- char '['
+  year <- read <$> many1 digit :: Parser Int
+  _ <- char '-'
+  month <- read <$> many1 digit :: Parser Int
+  _ <- char '-'
+  day <- read <$> many1 digit :: Parser Int
+  _ <- space
+  hour <- read <$> many1 digit :: Parser Int
+  _ <- char ':'
+  minute <- read <$> many1 digit :: Parser Int
+  _ <- char ']'
+  spaces
+  event <-     try (do _ <- string "Guard #"
+                       gId <- read <$> many1 digit :: Parser Int
+                       _ <- string " begins shift"
+                       return $ BeginShift gId)
+           <|> try (do _ <- string "falls asleep"
+                       return FallAsleep)
+           <|> try (do _ <- string "wakes up"
+                       return WakeUp)
+  let datetime = logDateTime year month day hour minute
+  return $ LogEntry datetime event
+
+inputParser :: Parser [LogEntry]
+inputParser = do
+  allClaims <- rowParser `sepEndBy` newline
+  eof
+  return allClaims
+
+data GuardState = Awake | Asleep
+
+orderedEventsToStats :: [LogEntry] -> Map Int [Word64]
+orderedEventsToStats (LogEntry _ (BeginShift firstGId) : events) =
+  let addLog gId log =
+        Map.alter (\case Nothing -> Just [log]
+                         Just prev -> Just (log : prev)) gId
+
+      extendLog from to Asleep log | from < to =
+        extendLog (from + 1) to Asleep (log `setBit` from)
+      extendLog _ _ _ log = log
+
+      combine gId from state log [] res =
+        let log' = extendLog from 59 state log
+        in addLog gId log' res
+      combine gId from state log
+        (LogEntry _ (BeginShift newGId) : events') res =
+        let log' = extendLog from 59 state log
+        in combine newGId 0 Awake 0 events' (addLog gId log' res)
+      combine gId from state log
+        (LogEntry (LogDateTime _ (LogTime _ minute)) FallAsleep : events') res =
+        let log' = extendLog from minute state log
+        in combine gId minute Asleep log' events' res
+      combine gId from state log
+        (LogEntry (LogDateTime _ (LogTime _ minute)) WakeUp : events') res =
+        let log' = extendLog from minute state log
+        in combine gId minute Awake log' events' res
+
+  in combine firstGId 0 Awake 0 events Map.empty
+
+orderedEventsToStats unexpected =
+  perror "Unexpected first log entry: %s" unexpected
+
+perMinutStats :: [Word64] -> [Int]
+perMinutStats logs =
+  let addLog res log =
+        map (\(i, r) -> if log `testBit` i then r + 1 else r)
+        $ zip [0..] res
+  in foldl' addLog (replicate 60 0) logs
+
+strategy1 :: Map Int [Word64] -> Int
+strategy1 stats =
+  let sleepAmounts = Map.map (foldl' (\a v -> a + popCount v) 0) stats
+      topSleeper = fst . maximumBy (comparing snd) $ Map.toList sleepAmounts
+      topSleeperStats = perMinutStats $ stats Map.! topSleeper
+      bestMinute =
+        fst . maximumBy (comparing snd) $ zip [0..] topSleeperStats
+  in topSleeper * bestMinute
+
+strategy2 :: Map Int [Word64] -> Int
+strategy2 stats =
+  let perMinute = Map.map perMinutStats stats
+      sameMinuteMax = Map.map maximum perMinute
+      (topSleeper, maxMinute) =
+        maximumBy (comparing snd) $ Map.toList sameMinuteMax
+      (Just bestMinute) = elemIndex maxMinute $ perMinute Map.! topSleeper
+  in topSleeper * bestMinute
+
+main :: IO ()
+main = do
+  input <- getContents
+  case parse inputParser "<input>" input of
+    Left errorText -> print errorText
+    Right events -> do
+      let orderedEvents = sortOn unLogDateTime events
+          stats = orderedEventsToStats orderedEvents
+      print $ strategy1 stats
+      print $ strategy2 stats

day4/stack.yaml

@@ -0,0 +1,64 @@
+# This file was automatically generated by 'stack init'
+#
+# Some commonly used options have been documented as comments in this file.
+# For advanced use and comprehensive documentation of the format, please see:
+# https://docs.haskellstack.org/en/stable/yaml_configuration/
+
+# Resolver to choose a 'specific' stackage snapshot or a compiler version.
+# A snapshot resolver dictates the compiler version and the set of packages
+# to be used for project dependencies. For example:
+#
+# resolver: lts-3.5
+# resolver: nightly-2015-09-21
+# resolver: ghc-7.10.2
+#
+# The location of a snapshot can be provided as a file or url. Stack assumes
+# a snapshot provided as a file might change, whereas a url resource does not.
+#
+# resolver: ./custom-snapshot.yaml
+# resolver: https://example.com/snapshots/2018-01-01.yaml
+resolver: lts-12.21
+
+# User packages to be built.
+# Various formats can be used as shown in the example below.
+#
+# packages:
+# - some-directory
+# - https://example.com/foo/bar/baz-0.0.2.tar.gz
+# - location:
+#    git: https://github.com/commercialhaskell/stack.git
+#    commit: e7b331f14bcffb8367cd58fbfc8b40ec7642100a
+# - location: https://github.com/commercialhaskell/stack/commit/e7b331f14bcffb8367cd58fbfc8b40ec7642100a
+#  subdirs:
+#  - auto-update
+#  - wai
+packages:
+- .
+# Dependency packages to be pulled from upstream that are not in the resolver
+# using the same syntax as the packages field.
+# (e.g., acme-missiles-0.3)
+# extra-deps: []
+
+# Override default flag values for local packages and extra-deps
+# flags: {}
+
+# Extra package databases containing global packages
+# extra-package-dbs: []
+
+# Control whether we use the GHC we find on the path
+# system-ghc: true
+#
+# Require a specific version of stack, using version ranges
+# require-stack-version: -any # Default
+# require-stack-version: ">=1.9"
+#
+# Override the architecture used by stack, especially useful on Windows
+# arch: i386
+# arch: x86_64
+#
+# Extra directories used by stack for building
+# extra-include-dirs: [/path/to/dir]
+# extra-lib-dirs: [/path/to/dir]
+#
+# Allow a newer minor version of GHC than the snapshot specifies
+# compiler-check: newer-minor