63. Unique Paths II (Graph; DP)

Follow up for "Unique Paths":

Now consider if some obstacles are added to the grids. How many unique paths would there be?

An obstacle and empty space is marked as 1 and 0 respectively in the grid.

For example,

There is one obstacle in the middle of a 3x3 grid as illustrated below.

[
  [0,0,0],
  [0,1,0],
  [0,0,0]
]

The total number of unique paths is 2.

class Solution {
public:
    int uniquePathsWithObstacles(vector<vector<int> > &obstacleGrid) {
        int m = obstacleGrid.size();
        int n = obstacleGrid[].size();
        int dp[m][n];

        if(obstacleGrid[][] == ) return ;
        dp[][] = ;
        for(int i = ; i< n; i++ )
        {
            if(obstacleGrid[][i] == ) dp[][i] = ;
            else dp[][i] = dp[][i-];
        }
        for(int i = ; i< m; i++ )
        {
            if(obstacleGrid[i][] == ) dp[i][] = ;
            else dp[i][] = dp[i-][];
        }

        for(int i = ; i< m; i++)
        {
            for(int j = ; j< n; j++)
            {
                if(obstacleGrid[i][j] == ) dp[i][j] = ;
                else dp[i][j] = dp[i-][j] + dp[i][j-];
            }
        }
        return dp[m-][n-];
    }
};