leetcode之Unique Paths II

class Solution(object):
def uniquePathsWithObstacles(self, obstacleGrid):
"""
:type obstacleGrid: List[List[int]]
:rtype: int
"""
if obstacleGrid[len(obstacleGrid) - 1][len(obstacleGrid[0]) - 1] == 1:
return 0
for i in range(len(obstacleGrid)):
for j in range(len(obstacleGrid[0])):
if obstacleGrid[i][j] == 0:
obstacleGrid[i][j] = 1
else:
obstacleGrid[i][j] = 0
#去除边界的阻碍的情况
for i in range(len(obstacleGrid))[::-1]:
if obstacleGrid[i][-1] == 0:
for j in range(i):
obstacleGrid[j][-1] = 0
break

for i in range(len(obstacleGrid[0]))[::-1]:
if obstacleGrid[-1][i] == 0:
for j in range(i):
print j, i
obstacleGrid[-1][j] = 0
break
#去除中间有阻碍的情况
for i in range(len(obstacleGrid) - 1)[::-1]:
for j in range(len(obstacleGrid[0]) - 1)[::-1]:
if obstacleGrid[i][j] != 0:
if obstacleGrid[i + 1][j] != 0 and obstacleGrid[i][j + 1] != 0:
obstacleGrid[i][j] = obstacleGrid[i][j + 1] + obstacleGrid[i + 1][j]
elif obstacleGrid[i + 1][j] == 0 and obstacleGrid[i][j + 1] == 0:
obstacleGrid[i][j] = 0
elif obstacleGrid[i + 1][j] == 0:
obstacleGrid[i][j] = obstacleGrid[i][j + 1]
else:
obstacleGrid[i][j] = obstacleGrid[i + 1][j]
return obstacleGrid[0][0]