corner
below
diagram
obstacles
图片说明
java

class Solution {
    public int uniquePathsWithObstacles(int[][] g) {
        int x = g.length ;
        int y = g[0].length;
        int arr[][] = new int [x][y];
        for(int i = 0 ; i < x ; i++){
            for(int j = 0 ; j < y ; j++){
                if(g[i][j]!=0) continue;
                if(i==0&&j==0)arr[i][j] =1 ;
                if(j> 0 )arr[i][j] += arr[i][j-1];
                if(i> 0 )arr[i][j] += arr[i-1][j];
            }
        }
        return arr[x-1][y-1];
    }
}

python