Unique Path ii

unique_paths_with_obstacles.py

class Solution:
    def uniquePathsWithObstacles(self, OG: List[List[int]]) -> int:
        if OG[0][0]: return 0
        m, n = len(OG), len(OG[0])
        dp = [[0] * n for _ in range(m)]
        dp[0][0] = 1
        for i in range(m):
            for j in range(n):
                if OG[i][j] or (i == 0 and j == 0): continue
                dp[i][j] = (dp[i-1][j] if i else 0) + (dp[i][j-1] if j else 0)
        return dp[m-1][n-1]