Day 13

3 files changed, 65 insertions, 0 deletions

diff --git a/2017/.gitignore b/2017/.gitignore
index 7d8d720..b8318ef 100644
--- a/2017/.gitignore
+++ b/2017/.gitignore
@@ -2,3 +2,4 @@
 *.o
 *.dSYM
 ?
+??
diff --git a/2017/13.hs b/2017/13.hs
new file mode 100644
index 0000000..77254ca
--- /dev/null
+++ b/2017/13.hs
@@ -0,0 +1,21 @@
+import Control.Monad
+import Data.Char
+import Data.List
+import Data.Maybe
+
+
+l2t :: [a] -> (a,a)
+l2t [a,b] = (a,b)
+
+check :: [(Int, Int)] -> Int -> Bool
+check inp off = all (\(d,r) -> if (d + off) `mod` (2 * (r - 1)) == 0 then False else True) inp
+
+cost :: [(Int, Int)] -> Int -> Int
+cost inp off = sum $ map (\(d,r) -> if (d + off) `mod` (2 * (r - 1)) == 0 then d * r else 0) inp
+
+main :: IO ()
+main = do
+    input <- liftM (map (l2t . map (read . takeWhile isDigit) . words) . lines) (readFile "13.in")
+
+    print $ cost input 0
+    print $ fromJust $ findIndex id $ map (check input) [0..]
diff --git a/2017/13.in b/2017/13.in
new file mode 100644
index 0000000..a1de9f9
--- /dev/null
+++ b/2017/13.in
@@ -0,0 +1,43 @@
+0: 3
+1: 2
+2: 6
+4: 4
+6: 4
+8: 8
+10: 9
+12: 8
+14: 5
+16: 6
+18: 8
+20: 6
+22: 12
+24: 6
+26: 12
+28: 8
+30: 8
+32: 10
+34: 12
+36: 12
+38: 8
+40: 12
+42: 12
+44: 14
+46: 12
+48: 14
+50: 12
+52: 12
+54: 12
+56: 10
+58: 14
+60: 14
+62: 14
+64: 14
+66: 17
+68: 14
+72: 14
+76: 14
+80: 14
+82: 14
+88: 18
+92: 14
+98: 18