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#!/usr/bin/python3
# START PART 1
SEGMENTS = 2
# END PART 1 START PART 2
SEGMENTS = 10
# END PART 2
position = tuple[int, int]
class Segment:
def __init__(self):
self.x = 0
self.y = 0
def track(self, pos: position) -> None:
x, y = pos
dx = x - self.x
dy = y - self.y
nx = 1 if dx > 0 else -1
ny = 1 if dy > 0 else -1
match (abs(dx), abs(dy)):
case (2, 0):
self.x += nx
case (0, 2):
self.y += ny
case (2, 1) | (2, 2) | (1, 2):
self.x += nx
self.y += ny
@property
def pos(self) -> position:
return self.x, self.y
def main() -> None:
with open("input", "r") as f:
data = [(xs[0], int(xs[1])) for xs in [l.split() for l in f.readlines()]]
snake = [Segment() for _ in range(SEGMENTS)]
head = snake[0]
tail = snake[-1]
locs: set[position] = set()
for d, c in data:
for _ in range(c):
match d:
case "U":
head.y += 1
case "D":
head.y -= 1
case "R":
head.x += 1
case "L":
head.x -= 1
for i, segment in enumerate(snake[1:]):
segment.track(snake[i].pos)
locs.add(tail.pos)
print(len(locs))
if __name__ == "__main__":
main()
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