Unique Paths II

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.

Note: m and n will be at most 100.

class Solution {
public:
    int uniquePathsWithObstacles(vector<vector<int> > &obstacleGrid) {
        int m=obstacleGrid.size();
        int n=obstacleGrid[0].size();
        int d[111][111];
        memset(d,0,sizeof(d));
        if(!obstacleGrid[0][0]) d[0][0]=1;
        for(int i=1;i<m;i++){
            if(obstacleGrid[i][0]) d[i][0]=0;
            else                   d[i][0]=d[i-1][0];
        }
        for(int i=1;i<n;i++){
            if(obstacleGrid[0][i]) d[0][i]=0;
            else                   d[0][i]=d[0][i-1];
        }
        for(int i=1;i<m;i++){
            for(int j=1;j<n;j++){
                if(obstacleGrid[i][j]) d[i][j]=0;
                else                   d[i][j]=d[i-1][j]+d[i][j-1];
            }
        }
        return d[m-1][n-1];
    }
};