[LeetCode] 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.

分析：类似于unique path

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