#63

Unique Paths II

specialist · 955 · lc medium +32 · verified · 44.2% accepted · 9,641 likes · top 26%

Description

A robot starts at grid[0][0] and can only move right or down in an m x n grid where 1 marks an obstacle and 0 is open. Return the number of distinct paths from start to grid[m-1][n-1]. The answer fits within 2 * 10⁹.

Example 1:

Input: obstacleGrid = [[0,0,0],[0,1,0],[0,0,0]]

Output: 2

Explanation: There is one obstacle in the middle of the 3x3 grid above.

There are two ways to reach the bottom-right corner:

1. Right -> Right -> Down -> Down

2. Down -> Down -> Right -> Right

Example 2:

Input: obstacleGrid = [[0,1],[0,0]]

Output: 1

Code

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class Solution:
    def uniquePathsWithObstacles(self, obstacleGrid: List[List[int]]) -> int:

class Solution:
    def uniquePathsWithObstacles(self, obstacleGrid: List[List[int]]) -> int: