Day 3 solution 1
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@ -31,6 +31,7 @@ library
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Day1
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Day2
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other-modules:
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Day3
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Paths_adventofcode
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build-depends:
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base >=4.7 && <5
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62
src/Day3.hs
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62
src/Day3.hs
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{-# LANGUAGE NoImplicitPrelude #-}
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{-# LANGUAGE OverloadedStrings #-}
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{-|
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description:
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--- Day 3: Spiral Memory ---
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You come across an experimental new kind of memory stored on an infinite two-dimensional grid.
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Each square on the grid is allocated in a spiral pattern starting at a location marked 1 and then counting up while spiraling outward. For example, the first few squares are allocated like this:
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17 16 15 14 13
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18 5 4 3 12
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19 6 1 2 11
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20 7 8 9 10
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21 22 23---> ...
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While this is very space-efficient (no squares are skipped), requested data must be carried back to square 1 (the location of the only access port for this memory system) by programs that can only move up, down, left, or right. They always take the shortest path: the Manhattan Distance between the location of the data and square 1.
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For example:
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- Data from square 1 is carried 0 steps, since it's at the access port.
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- Data from square 12 is carried 3 steps, such as: down, left, left.
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- Data from square 23 is carried only 2 steps: up twice.
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- Data from square 1024 must be carried 31 steps.
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How many steps are required to carry the data from the square identified in your puzzle input all the way to the access port?
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|-}
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module Day2 where
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import Protolude
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import qualified Control.Foldl as F
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import Data.List (words,lines)
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input = 265149
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blocks l (previ,prevx,prevy) =
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concat [[(previ + 1 + n, prevx + 1, prevy + n) | n <- [0..l]]
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, [(previ + 2 + l + n, prevx - n, prevy + l) | n <- [0..l]]
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, [(previ + 3 + 2*l + n, prevx - l, prevy + l - n - 1) | n <- [0..l]]
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, [(previ + 4 + 3*l + n, prevx - l + n + 1, prevy - 1) | n <- [0..l]]
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]
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block1 = [ (2,1,0)
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, (3,1,1)
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, (4,0,1)
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, (5,-1,1)
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, (6,-1,0)
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, (7,-1,-1)
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, (8,0,-1)
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, (9,1,-1)
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]
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spiral = (1,0,0):concatMap (\n -> blocks (n+1) ((n+1)^2,n `div` 2,- (n `div` 2))) [0,2..]
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returnPathLength i =
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drop (i - 1) spiral
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& head
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& fmap (\(_,x,y) -> abs x + abs y)
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