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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,55 @@ | ||
| from utils import lines, Point | ||
| from collections import deque, namedtuple, defaultdict | ||
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| Node = namedtuple('Node', ['position', 'origin']) | ||
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| def parse(lines): | ||
| heights = {} | ||
| trailheads = [] | ||
| peaks = [] | ||
| for y, line in enumerate(lines): | ||
| for x, h in enumerate(map(int, line)): | ||
| p = Point(x, y) | ||
| heights[p] = h | ||
| if h == 0: | ||
| trailheads.append(p) | ||
| if h == 9: | ||
| peaks.append(p) | ||
| return heights, trailheads, peaks | ||
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| def part1(heights, peaks): | ||
| reachable = defaultdict(set) | ||
| score = defaultdict(int) | ||
| fringe = deque(Node(p, p) for p in peaks) | ||
| while fringe: | ||
| pos, origin = fringe.popleft() | ||
| for n in pos.neighbors(): | ||
| if n not in heights or heights[n] != heights[pos] - 1 or n in reachable[origin]: | ||
| continue | ||
| reachable[origin].add(n) | ||
| if heights[n] == 0: | ||
| score[n] += 1 | ||
| else: | ||
| fringe.append(Node(n, origin)) | ||
| return sum(score.values()) | ||
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| def part2(heights, trailheads): | ||
| rating = defaultdict(int) | ||
| fringe = deque(Node(p, p) for p in trailheads) | ||
| while fringe: | ||
| pos, origin = fringe.popleft() | ||
| for n in pos.neighbors(): | ||
| if n not in heights or heights[n] != heights[pos] + 1: | ||
| continue | ||
| if heights[n] == 9: | ||
| rating[origin] += 1 | ||
| else: | ||
| fringe.append(Node(n, origin)) | ||
| return sum(rating.values()) | ||
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| if __name__ == '__main__': | ||
| heights, trailheads, peaks = parse(lines()) | ||
| print(part1(heights, peaks)) | ||
| print(part2(heights, trailheads)) |
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,22 @@ | ||
| def lines(): | ||
| while True: | ||
| try: | ||
| yield input() | ||
| except: | ||
| break | ||
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| class Point: | ||
| def __init__(self, x, y): self.x, self.y = x, y | ||
| def neighbor(self, D): return self + [(0,-1),(1,0),(0,1),(-1,0)][D] | ||
| def neighbors(self): | ||
| for i in range(4): | ||
| yield self.neighbor(i) | ||
| def __add__(self, other): return Point(self.x + other[0], self.y + other[1]) | ||
| def __sub__(self, other): return Point(self.x - other[0], self.y - other[1]) | ||
| def __neg__(self): return Point(-self.x, -self.y) | ||
| def __eq__(self, other): return self.x == other[0] and self.y == other[1] | ||
| def __getitem__(self, i): return self.x if i == 0 else self.y | ||
| def __str__(self): return "({}, {})".format(self.x, self.y) | ||
| def __repr__(self): return "({} {})".format(self.x, self.y) | ||
| def __hash__(self): return (self.x, self.y).__hash__() | ||
| #def __contains__(self, other): return other.x in range(self.x) and other.y in range(self.y) |
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