From 8f030af74c4b39732d73abfb60d62121b27bedc9 Mon Sep 17 00:00:00 2001
From: Sijmen Schoon <me@sijmenschoon.nl>
Date: Sun, 2 Dec 2018 16:52:36 +0100
Subject: [PATCH] Add day2 and readd day1

---
 .gitignore    |  2 ++
 Day1/Day1A.hs |  8 ++++++++
 Day1/Day1B.hs | 14 ++++++++++++++
 Day2/Day2A.hs | 18 ++++++++++++++++++
 Day2/Day2B.hs | 25 +++++++++++++++++++++++++
 5 files changed, 67 insertions(+)
 create mode 100644 Day1/Day1A.hs
 create mode 100644 Day1/Day1B.hs
 create mode 100644 Day2/Day2A.hs
 create mode 100644 Day2/Day2B.hs

diff --git a/.gitignore b/.gitignore
index 65dd287..cd4e12a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,7 +1,9 @@
 # Ignore everything without extension
 *
+!*.*
 !*/
 
 *.in
 *.hi
 *.o
+*.prof
diff --git a/Day1/Day1A.hs b/Day1/Day1A.hs
new file mode 100644
index 0000000..4ed7b42
--- /dev/null
+++ b/Day1/Day1A.hs
@@ -0,0 +1,8 @@
+module Day1A where
+
+read' :: String -> Int
+read' ('+':str) = read str
+read' str = read str
+
+main :: IO ()
+main = interact $ show . sum . map read' . lines
diff --git a/Day1/Day1B.hs b/Day1/Day1B.hs
new file mode 100644
index 0000000..04db47a
--- /dev/null
+++ b/Day1/Day1B.hs
@@ -0,0 +1,14 @@
+module Day1B where
+
+import Day1A (read')
+import qualified Data.IntSet as S
+
+handle :: Int -> S.IntSet -> [Int] -> Int
+handle freq history (nextDelta:xs)
+  | S.member freq history = freq  -- When the frequency is in the history set, return it
+  | otherwise             = handle (freq + nextDelta) (S.insert freq history) xs  -- Recurse otherwise
+handle _ _ _ = error "xs should not be empty :("
+
+main :: IO ()
+main = interact $ show . handle 0 S.empty . deltaFreqs
+  where deltaFreqs = cycle . map read' . lines  -- Convert input to Ints and repeat infinitely
diff --git a/Day2/Day2A.hs b/Day2/Day2A.hs
new file mode 100644
index 0000000..b6526a4
--- /dev/null
+++ b/Day2/Day2A.hs
@@ -0,0 +1,18 @@
+module Day2A where
+
+import qualified Data.IntMap as IM
+import Data.Char (ord)
+
+out :: String -> Int -> Int
+out id' n = min (length $ IM.filter (==n) counts) 1
+  where counts = foldr (\c -> IM.insertWith (+) (ord c) 1) IM.empty id'
+
+handleId :: String -> (Int, Int)
+handleId id' = (out id' 2, out id' 3)
+
+add2 :: Num a => (a, a) -> (a, a) -> (a, a)
+add2 (a, b) (x, y) = (a + x, b + y)
+
+main :: IO ()
+main = interact $ show . uncurry (*) . counts . lines
+  where counts = foldr (add2 . handleId) (0, 0)
diff --git a/Day2/Day2B.hs b/Day2/Day2B.hs
new file mode 100644
index 0000000..0ba6b24
--- /dev/null
+++ b/Day2/Day2B.hs
@@ -0,0 +1,25 @@
+{-# LANGUAGE TupleSections #-}
+module Day2B where
+import Data.List (find)
+import qualified Data.Sequence as S
+import qualified Data.Foldable as F
+
+dist' :: Int -> (S.Seq Char) -> String -> String -> (Int, String)
+dist' n common (a:x) (b:y)
+  | a == b    = dist' n (common S.|> a) x y
+  | otherwise = dist' (n + 1) common x y
+dist' n common _ _ = (n, F.toList common)
+
+dist :: String -> String -> (Int, String)
+dist = dist' 0 S.empty
+
+combinations :: [String] -> [(String, String)]
+combinations (x:y:xs) = (x, y):(combinations (y:xs))
+combinations [] = []
+
+distances :: [(String, String)] -> String
+distances xs = result
+  where Just(_, result) = find (\(x, _) -> x == 1) $ map (uncurry dist) xs
+
+main :: IO ()
+main = interact $ distances . combinations . lines