68 lines
1.6 KiB
Python
68 lines
1.6 KiB
Python
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def get_neighbors(grid, current):
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neighbors = []
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y, x = current
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cur_height = ord(grid[y][x])
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if (grid[y][x] == "S"):
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cur_height = ord("a")
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for i in range(-1, 2):
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for j in range(-1, 2):
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if i == 0 and j == 0 or (i != 0 and j != 0):
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continue
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if (y + i) < 0 or (y + i) >= len(grid):
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continue
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if (x + j) < 0 or (x + j) >= len(grid[y + i]):
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continue
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new_height = ord(grid[y + i][x + j])
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if (grid[y + i][x + j] == "E"):
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new_height = ord("z")
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if abs(new_height - cur_height) <= 1 or new_height <= cur_height:
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neighbors.append((y + i, x + j))
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return neighbors
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def bfs(grid, start, end):
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queue = []
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queue.append(start)
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visited = {}
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visited[start] = 0
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while queue:
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current = queue.pop(0)
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if current == end:
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return visited[current]
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for neighbor in get_neighbors(grid, current):
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if neighbor not in visited:
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queue.append(neighbor)
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visited[neighbor] = visited[current] + 1
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return False
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def main():
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file = open("input", "r")
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grid = file.readlines()
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file.close()
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start = (0, 0)
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end = (0, 0)
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for i in range(len(grid)):
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for j in range(len(grid[i])):
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if grid[i][j] == "S":
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start = (i, j)
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elif grid[i][j] == "E":
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end = (i, j)
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best = bfs(grid, start, end)
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print(best)
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for i in range(len(grid)):
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for j in range(len(grid[i])):
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if grid[i][j] == "a":
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this_as_start = bfs(grid, (i, j), end)
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if this_as_start and this_as_start < best:
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best = this_as_start
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print(best)
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if __name__ == "__main__":
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main()
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