59 lines
1.7 KiB
Nim
59 lines
1.7 KiB
Nim
import std/[strutils, sequtils, options, math, parseutils, sets, strformat, algorithm, tables]
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import ./common
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proc toPointPair(s: string): (int, int, int, int) =
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let nums = s.split(" -> ").mapIt(it.split(',').mapIt(it.parseInt())).concat()
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(nums[0], nums[1], nums[2], nums[3])
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proc part1(inputLines: seq[string]): int =
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var points: CountTable[(int, int)] = initCountTable[(int, int)](1000)
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for l in inputLines:
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let (x1, y1, x2, y2) = l.toPointPair()
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if x1 == x2 or y1 == y2:
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for x in min(x1, x2)..max(x1, x2):
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for y in min(y1, y2)..max(y1, y2):
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points.inc((x, y))
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for p in points.values():
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if p >= 2:
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inc result
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proc part2(inputLines: seq[string]): int =
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var points: CountTable[(int, int)] = initCountTable[(int, int)](1000)
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for l in inputLines:
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let (x1, y1, x2, y2) = l.toPointPair()
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let ang = arctan2(float(y2 - y1), float(x2 - x1)) * 180 / PI
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if (ang.abs() mod 90) == 45.0:
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var x = x1
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var y = y1
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let xd = if x1 > x2: -1 else: 1
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let yd = if y1 > y2: -1 else: 1
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while x >= min(x1, x2) and x <= max(x1, x2) and y >= min(y1, y2) and y <= max(y1, y2):
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points.inc((x, y))
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x += xd
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y += yd
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elif x1 == x2 or y1 == y2:
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for x in min(x1, x2)..max(x1, x2):
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for y in min(y1, y2)..max(y1, y2):
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points.inc((x, y))
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for p in points.values():
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if p >= 2:
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inc result
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let input = 5.loadInput()
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time("day 5 part 1"): echo input.part1()
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time("day 5 part 2"): echo input.part2()
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when not defined(release):
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let testInput = """0,9 -> 5,9
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8,0 -> 0,8
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9,4 -> 3,4
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2,2 -> 2,1
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7,0 -> 7,4
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6,4 -> 2,0
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0,9 -> 2,9
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3,4 -> 1,4
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0,0 -> 8,8
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5,5 -> 8,2""".split('\n')
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doAssert testInput.part1() == 5
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doAssert testInput.part2() == 12
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