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
     
      
       >& obstacleGrid) {        int m = obstacleGrid.size();        int n = obstacleGrid[0].size();                vector
       
        
          > resu(m+1, vector
         
          (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];    }