you are in charge of preparing a recently purchased lot
from collections import defaultdict
from collections import deque
def is_valid(i, j, m, n, matrix, visited):
if i >= 0 and j >= 0 \
and i < m and j < n \
and visited[i][j] is False \
and matrix[i][j] in (1, 9):
return True
return False
def remove_obstacle(matrix, m, n):
queue = deque()
i = 0
j = 0
queue.append((i, j, 0))
visited = [[False for _ in range(n)] for _ in range(m)]
distance_matrix = [[100 for _ in range(n)] for _ in range(m)]
visited[i][j] = True
while queue:
i, j, distance = queue.popleft()
distance_matrix[i][j] = distance
visited[i][j] = True
if matrix[i][j] == 9:
return distance
new_distance = distance + 1
if is_valid(i + 1, j, m, n, matrix, visited):
queue.append((i + 1, j, new_distance))
if is_valid(i - 1, j, m, n, matrix, visited):
queue.append((i - 1, j, new_distance))
if is_valid(i, j + 1, m, n, matrix, visited):
queue.append((i, j + 1, new_distance))
if is_valid(i, j - 1, m, n, matrix, visited):
queue.append((i, j - 1, new_distance))
return -1
if __name__ == '__main__':
m = 5
n = 4
l = [
[1, 1, 1, 1],
[0, 1, 1, 1],
[0, 1, 0, 1],
[1, 1, 9, 1],
[0, 0, 1, 1]
]
bfs = remove_obstacle(l, m, n)
assert bfs == 5
m = 3
n = 3
l = [
[1, 0, 0],
[1, 0, 0],
[1, 9, 1]
]
bfs = remove_obstacle(l, m, n)
assert bfs == 3