commit fffdcbfd5c08bc45c6f939b9842b9f9e7f2807b9 · drubery.com/aoc2025

+1 -1

input.sh

···

       1
       1
        
       #!/bin/bash

     

       2
       2
        
       

     

       3
       3
       -
       YEAR=2024

     

       3
       3
       +
       YEAR=2025

     

       4
       4
        
       DAY=$1

     

       5
       5
        
       COOKIE=$(cat cookie.txt)

     

       6
       6

+24 -2

src/Day1.hs

···

       1
       1
        
       module Day1 where

     

       2
       2
        
       

     

       3
       3
       +
       parseLine :: String -> (Char, Int)

     

       4
       4
       +
       parseLine (c : s) = (c, read s)

     

       5
       5
       +
       

     

       6
       6
       +
       parseInput :: String -> [(Char,Int)]

     

       7
       7
       +
       parseInput input = map parseLine $ lines input

     

       8
       8
       +
       

     

       9
       9
       +
       doRotations :: [(Char, Int)] -> Int -> [Int]

     

       10
       10
       +
       doRotations (('L', l) : rest) n = (n : doRotations rest ((n-l) `mod` 100))

     

       11
       11
       +
       doRotations (('R', r) : rest) n = (n : doRotations rest ((n+r) `mod` 100))

     

       12
       12
       +
       doRotations [] n = [n]

     

       13
       13
       +
       

     

       14
       14
       +
       getCrossings :: [(Char, Int)] -> Int -> [Int]

     

       15
       15
       +
       getCrossings (('L', l) : rest) n = (((l-n) `div` 100) + (if n > 0 then 1 else 0) : getCrossings rest ((n-l) `mod` 100))

     

       16
       16
       +
       getCrossings (('R', r) : rest) n = (((n+r) `div` 100) : getCrossings rest ((n+r) `mod` 100))

     

       17
       17
       +
       getCrossings [] _ = []

     

       18
       18
       +
       

     

       3
       19
        
       part1 :: String -> String

     

       4
       4
       -
       part1 _ = "Day 1 part 1"

     

       20
       20
       +
       part1 input =

     

       21
       21
       +
         let rotations = parseInput input

     

       22
       22
       +
             states = doRotations rotations 50

     

       23
       23
       +
          in show $ length (filter (== 0) states)

     

       5
       24
        
       

     

       6
       25
        
       part2 :: String -> String

     

       7
       7
       -
       part2 _ = "Day 1 part 2"

     

       26
       26
       +
       part2 input =

     

       27
       27
       +
         let rotations = parseInput input

     

       28
       28
       +
             zeroCrossings = getCrossings rotations 50

     

       29
       29
       +
           in show $ sum zeroCrossings