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.

解题报告：Unique Paths II 是Unique Paths 的升级版，多一个数组存了1代表障碍这点走不通，所以我们解决的时候，也要多一步判断。不难

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

              if(obstacleGrid[i][j] != 1) {
                  if(i != m-1) {
                   if(temp[i+1][j] != -1)
                    temp[i+1][j] += temp[i][j];
                   else
                    temp[i+1][j] = temp[i][j] ;
                }}
                else
                    temp[i][j] = 0 ;

            }
         }
         return temp[m-1][n-1];
    }
};

LeetCode-Unique Paths II