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Clean day 12.

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This commit is contained in:
Mikael CAPELLE 2022-12-12 10:48:37 +01:00
parent 5004aa3376
commit 792951afa8
1 changed files with 21 additions and 17 deletions
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38
2022/day12.py
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@ -2,6 +2,7 @@
import heapq
import sys
from typing import Iterator
def dijkstra(
@ -13,21 +14,7 @@ def dijkstra(
def heuristic(row: int, col: int) -> int:
return abs(end[0] - row) + abs(end[1] - col)
queue: list[tuple[tuple[int, int], tuple[int, int]]] = []
visited: set[tuple[int, int]] = set()
lengths: dict[tuple[int, int], int] = {}
parents: dict[tuple[int, int], tuple[int, int]] = {}
heapq.heappush(queue, ((heuristic(start[0], start[1]), 0), start))
while queue:
(_, length), (c_row, c_col) = heapq.heappop(queue)
visited.add((c_row, c_col))
if (c_row, c_col) == end:
break
def neighbors(row: int, col: int) -> Iterator[tuple[int, int]]:
for n_row, n_col in (
(c_row - 1, c_col),
(c_row + 1, c_col),
@ -38,10 +25,27 @@ def dijkstra(
if not (n_row >= 0 and n_row < n_rows and n_col >= 0 and n_col < n_cols):
continue
if (n_row, n_col) in visited:
if grid[n_row][n_col] > grid[c_row][c_col] + 1:
continue
if grid[n_row][n_col] > grid[c_row][c_col] + 1:
yield n_row, n_col
queue: list[tuple[tuple[int, int], tuple[int, int]]] = []
visited: set[tuple[int, int]] = set()
lengths: dict[tuple[int, int], int] = {}
parents: dict[tuple[int, int], tuple[int, int]] = {}
heapq.heappush(queue, ((heuristic(start[0], start[1]), 0), start))
while queue and (end not in visited):
(_, length), (c_row, c_col) = heapq.heappop(queue)
visited.add((c_row, c_col))
for n_row, n_col in neighbors(c_row, c_col):
if (n_row, n_col) in visited:
continue
if length + 1 < lengths.get((n_row, n_col), n_rows * n_cols):