70 lines
1.6 KiB
Nim
70 lines
1.6 KiB
Nim
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import ./common, std/[sequtils, algorithm, sugar, sets, strformat, strutils, tables]
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type
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Axis = enum X, Y
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Points = HashSet[(int, int)]
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Fold = (Axis, int)
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Folds = seq[Fold]
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proc parse(input: Lines): (Points, Folds) =
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var parsingFolds = false
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for l in input.mapIt it.strip:
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if l == "": parsingFolds = true; continue
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if not parsingFolds:
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let coords = l.split(',').map parseInt
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result[0].incl (coords[0], coords[1])
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else:
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result[1].add ((if l.contains 'x': X else: Y), l.split('=')[1].parseInt)
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proc printPoints(points: Points): void =
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var w, h = 0
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for (x, y) in points:
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w = max(w, x)
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h = max(h, y)
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var lines: Lines = @[]
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for y in 0..h: lines.add(' '.repeat(w+1))
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for (x, y) in points: lines[y][x] = '#'
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for l in lines: echo l
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proc doFold(points: Points, f: Fold): Points =
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let (axis, n) = f
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for (x, y) in points:
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if (axis == X and x > n): result.incl((n - (x - n), y))
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elif (axis == Y and y > n):
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result.incl((x, n - (y - n)))
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else: result.incl((x, y))
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proc p1(input: Lines): int =
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let (points, folds) = input.parse()
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points.doFold(folds[0]).len()
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proc p2(input: Lines): int =
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let (points, folds) = input.parse()
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folds.reduce((points: Points, fold) => points.doFold(fold), points).printPoints()
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echo "You'll have to read this one on your own, captain."
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const input = @[
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"6,10",
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"0,14",
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"9,10",
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"0,3",
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"10,4",
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"4,11",
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"6,0",
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"6,12",
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"4,1",
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"0,13",
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"10,12",
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"3,4",
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"3,0",
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"8,4",
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"1,10",
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"2,14",
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"8,10",
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"9,0",
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"",
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"fold along y=7",
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"fold along x=5",
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]
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doDay 13, n => n.loadInput, p1, p2, (input, 17, 0)
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