Unique Paths II [LeetCode]

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.

Solution: The same to Unique Paths, just add obstacle check.

 class Solution {
 public:
     int uniquePathsWithObstacles(vector<vector<int> > &obstacleGrid) {
         if(obstacleGrid.size() <=  || obstacleGrid[].size() <= )
             return ;

         int row = obstacleGrid.size();
         int column = obstacleGrid[].size();
         vector<int> path_nums(column, );
         for(int i = ; i < row; i ++) {
             int row_idx = row -  - i;
             for(int j = ; j < column; j ++ ) {
                 int column_idx = column -  - j;
                 if(i ==  && j ==  && obstacleGrid[row_idx][column_idx] == )
                     return ;
                 if(i ==  && j ==  && obstacleGrid[row_idx][column_idx] == ) {
                     path_nums[j] = ;
                 }else {
                     if(obstacleGrid[row_idx][column_idx] == ) {
                         path_nums[j] = ;
                     }else {
                         if(j != )
                             path_nums[j] += path_nums[j - ];
                     }
                 }
             }
         }
         return path_nums[column - ];
     }
 };