aoc/day-11/sol.py
2022-12-11 22:27:34 -07:00

68 lines
1.6 KiB
Python

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