it's pretty familiar with the uniquePath solution, with some extra consideration

```
class Solution {
public:
int uniquePathsWithObstacles(vector<vector<int>> &grid) {
if (grid[0][0]) return 0;
int m = grid.size(), n = grid[0].size();
vector<int> cur(n, 1);
for (int i = 1; i < n; i++) {
cur[i] = cur[i - 1];
if (grid[0][i]) cur[i] = 0;
}
for (int i = 1; i < m; i++) {
if (grid[i][0]) cur[0] = 0;
for (int j = 1; j < n; j++)
if (grid[i][j])
cur[j] = 0;
else
cur[j] += cur[j - 1];
}
return cur[n - 1];
}
};
```