Pascal Lais
d16807f80d
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continuous-integration/drone/push Build is passing
82 lines
2.4 KiB
Python
82 lines
2.4 KiB
Python
#!/usr/bin/env python3
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from pathlib import Path
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from heapq import heappush, heappop
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def part_1(input):
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result = 0
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x_size = len(input[0].strip())
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y_size = len(input)
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nodes = {(x, y): int(v) for y, line in enumerate(input)
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for x, v in enumerate(line.strip())}
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start = (0, 0)
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end = (x_size - 1, y_size - 1)
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cost = {start: 0}
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queue = [(0, start)]
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done = set()
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neighbors = set([(-1, 0), (0, -1), (0, 1), (1, 0)])
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while len(queue):
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cur_cost, current = heappop(queue)
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if current in done:
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continue
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(xc, yc) = current
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next = set()
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for (xn, yn) in neighbors:
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nbr = (xc + xn, yc + yn)
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if nbr in nodes and not nbr in done:
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next.add(nbr)
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for n in next:
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next_cost = cur_cost + nodes[n]
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if not n in cost or next_cost < cost[n]:
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cost[n] = next_cost
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heappush(queue, (next_cost, n))
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done.add(current)
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result = cost[end]
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print("Part 1 result:", result)
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def part_2(input):
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result = 0
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x_size = len(input[0].strip())
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y_size = len(input)
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repeat = 5
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nodes = {(x, y): int(v) for y, line in enumerate(input)
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for x, v in enumerate(line.strip())}
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start = (0, 0)
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end = ((x_size * repeat) - 1, (y_size * repeat) - 1)
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cost = {start: 0}
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queue = [(0, start)]
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done = set()
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neighbors = set([(-1, 0), (0, -1), (0, 1), (1, 0)])
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while len(queue):
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cur_cost, current = heappop(queue)
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if current in done:
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continue
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(xc, yc) = current
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next = set()
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for (xn, yn) in neighbors:
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x = xc + xn
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y = yc + yn
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if 0 <= x < (x_size * repeat) and 0 <= y < (y_size * repeat):
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if not (x, y) in done:
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next.add((x, y))
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for (x, y) in next:
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next_cost = nodes[(x % x_size, y % y_size)] + \
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(x // x_size) + (y // y_size)
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if next_cost > 9:
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next_cost -= 9
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if not (x, y) in cost or (cur_cost + next_cost) < cost[(x, y)]:
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cost[(x, y)] = cur_cost + next_cost
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heappush(queue, (cur_cost + next_cost, (x, y)))
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done.add(current)
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result = cost[end]
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print("Part 2 result:", result)
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input = list()
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p = Path(__file__).with_name('input.txt')
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with open(p) as f:
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input = f.readlines()
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part_1(input)
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part_2(input)
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