create: 0063-unique-paths-ii.py

python/0063-unique-paths-ii.py

@@ -0,0 +1,23 @@
+class Solution:
+ def uniquePathsWithObstacles(self, mat: List[List[int]]) -> int:
+ m = len(mat)
+ n = len(mat[0])
+ prev = [0 for _ in range(n)]
+
+ for i in range(m):
+ curr = [0 for _ in range(n)]
+ for j in range(n):
+ if mat[i][j] == 1:
+ curr[j] = 0
+ elif i == 0 and j == 0:
+ curr[j] = 1
+ else:
+ up = 0
+ left = 0
+ if i>0:
+ up = prev[j]
+ if j > 0:
+ left = curr[j-1]
+ curr[j] = up + left
+ prev = curr
+ return prev[n-1]