Marijn/Advent-of-Code-2021
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Marijn Doeve
2021-12-15 13:52:02 +01:00
parent 7ea48928d5
commit 5ae8933fca
1 changed files with 9 additions and 12 deletions
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21
15/15.py
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@@ -1,10 +1,10 @@
import numpy as np import numpy as np
from heapq import heappush, heappop from heapq import heappush, heappop
import sys
def neighbors(pos: tuple[int, int], shape): def neighbors(pos: tuple[int, int], shape):
n = [] n = []
if pos[0] > 0: if pos[0] > 0:
n.append((pos[0] - 1, pos[1])) n.append((pos[0] - 1, pos[1]))
if pos[1] > 0: if pos[1] > 0:
@@ -19,22 +19,18 @@ def neighbors(pos: tuple[int, int], shape):
def dijkstra(grid): def dijkstra(grid):
dist = np.full_like(grid, np.iinfo(np.int64).max) dist = np.full_like(grid, np.iinfo(np.int64).max)
q = [(0, (0, 0))]
q = []
heappush(q, (0, (0, 0)))
dist[0, 0] = 0 dist[0, 0] = 0
while q: while q:
dist_u, u = heappop(q) _, u = heappop(q)
if dist[u] < dist_u:
continue
for neighbour in neighbors(u, grid.shape): for neighbour in neighbors(u, grid.shape):
if dist[neighbour] > dist[u] + grid[neighbour]: new = dist[u] + grid[neighbour]
dist[neighbour] = dist[u] + grid[neighbour]
heappush(q, (dist[neighbour], neighbour)) if dist[neighbour] > new:
dist[neighbour] = new
heappush(q, (new, neighbour))
return dist[(grid.shape[0] - 1, grid.shape[1] - 1)] return dist[(grid.shape[0] - 1, grid.shape[1] - 1)]
@@ -59,5 +55,6 @@ if __name__ == "__main__":
grid = np.array( grid = np.array(
[[int(x) for x in list(line.strip())] for line in sys.stdin.readlines()] [[int(x) for x in list(line.strip())] for line in sys.stdin.readlines()]
) )
print("Part one:", dijkstra(grid)) print("Part one:", dijkstra(grid))
print("Part two:", dijkstra(multiply_grid(grid))) print("Part two:", dijkstra(multiply_grid(grid)))