From 6d831177d2c874ca9888a70188f99ed92c900481 Mon Sep 17 00:00:00 2001
From: Yuchen Pei <me@ypei.me>
Date: Thu, 7 Dec 2017 15:34:27 +0100
Subject: finished puzzle5, 6, 7part1

---
 Puzzle6.hs | 41 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)
 create mode 100644 Puzzle6.hs

(limited to 'Puzzle6.hs')

diff --git a/Puzzle6.hs b/Puzzle6.hs
new file mode 100644
index 0000000..721aa9b
--- /dev/null
+++ b/Puzzle6.hs
@@ -0,0 +1,41 @@
+import Data.List (elemIndex)
+import Data.List.Split (splitOn)
+import Data.Maybe (fromJust)
+--import Control.Monad (liftM2)
+
+incList :: Int -> Int -> Int -> [Int]
+incList n q r = replicate r (q + 1) ++ replicate (n - r - 1) q
+
+f :: [Int] -> [Int]
+f xs = (drop (n - m) zs) ++ (take (n - m) zs)
+  where p = maximum xs
+        n = length xs
+        q = p `div` n
+        r = p `mod` n
+        m = (fromJust $ elemIndex p xs) + 1
+        ys = drop m (cycle xs)
+        zs = (take (n - 1) $ zipWith (+) ys (incList n q r)) ++ [q]
+
+g :: [[Int]] -> [[Int]]
+g xs = (f $ head xs):xs
+
+looped :: [Int] -> [[Int]]
+looped xs = until (\ys -> (head ys) `elem` (tail ys)) g [xs]
+
+solve1' :: [Int] -> Int
+solve1' xs = (length $ looped xs) - 1
+
+solve2' :: [Int] -> Int
+solve2' xs = let (y:ys) = looped xs in (fromJust $ elemIndex y ys) + 1
+
+parseInput :: [Char] -> [Int]
+parseInput xs = map read $ splitOn " " xs
+
+solve1 :: [Char] -> Int
+solve1 = solve1' . parseInput
+
+solve2 :: [Char] -> Int
+solve2 = solve2' . parseInput
+
+input :: [Char]
+input = "4 10 4 1 8 4 9 14 5 1 14 15 0 15 3 5"
-- 
cgit v1.2.3