blob: dcad9ed80bd7b78ff87a12ef9376b0835870505f (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
|
-- Author: Yuchen Pei (me@ypei.me)
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"
|
