95 lines
2.4 KiB
Nim
95 lines
2.4 KiB
Nim
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import std/strutils
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import std/sequtils
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import system
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type Pos = object
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X: int
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Y: int
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type Rope = object
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Head: Pos
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Tail: Pos
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proc move_rope(input: Rope, vec: Pos): Rope =
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var rope = input
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rope.Head.X += vec.X
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rope.Head.Y += vec.Y
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let deltaX = rope.Head.X - rope.Tail.X
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let deltaY = rope.Head.Y - rope.Tail.Y
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if not (abs(deltaX) >= 2 or abs(deltaY) >= 2): return rope
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if deltaX > 0:
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rope.Tail.X += 1
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elif deltaX < 0:
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rope.Tail.X -= 1
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if deltaY > 0:
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rope.Tail.Y += 1
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elif deltaY < 0:
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rope.Tail.Y -= 1
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return rope
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proc print_rope(r: Rope, width: int, height: int) =
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for y in -height .. height:
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for x in -width .. width:
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let ishead = (x == r.Head.X and y == r.Head.Y)
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let istail = (x == r.Tail.X and y == r.Tail.Y)
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let iszero = (x == 0 and y == 0 )
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if ishead and istail:
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io.stdout.write "@"
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elif ishead:
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io.stdout.write "H"
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elif istail:
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io.stdout.write "T"
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elif iszero:
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io.stdout.write "s"
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else:
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io.stdout.write "."
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io.stdout.write "\n"
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io.stdout.write "\n"
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proc run09_1(): string =
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const input = staticRead"../input/day09.txt"
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let lines = splitLines(input).filter(proc(p: string): bool = p != "")
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var rope = Rope(Head: Pos(X: 0, Y: 0), Tail: Pos(X: 0, Y: 0))
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var tailposmap = @[rope.Tail]
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# print_rope(rope, 200, 200)
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for line in lines:
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let dir = case line.split(" ")[0][0]:
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of 'U': Pos(X: 00, Y: -1)
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of 'D': Pos(X: 00, Y: +1)
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of 'L': Pos(X: -1, Y: 00)
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of 'R': Pos(X: +1, Y: 00)
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else: Pos(X: 00, Y: 00)
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let cnt = parseInt(line.split(" ")[1])
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for _ in 0 ..< cnt:
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# echo "== ", line, " ==", " (dir: [", dir.X, "|", dir.Y, "] )"
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rope = move_rope(rope, dir)
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tailposmap.add(rope.Tail)
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# print_rope(rope, 100, 100)
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#echo "[", rope.Tail.X, ";", rope.Tail.Y, "] -> [", rope.Head.X, ";", rope.Head.Y, "]"
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# echo tailposmap.deduplicate()
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return tailposmap.deduplicate().len().intToStr()
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when not defined(js):
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echo run09_1()
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else:
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proc js_run09_1(): cstring {.exportc.} =
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return cstring(run09_1())
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