[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

.

public class Solution {
public int uniquePathsWithObstacles(int[][] obstacleGrid) {
int row = obstacleGrid.length;
int column = obstacleGrid[0].length;
int[][] result = new int[row+1][column+1];

for(int i = row - 1; i >= 0; i--) {
for(int j = column - 1; j >= 0; j--) {
if(obstacleGrid[i][j] == 1) {
result[i][j] = 0;
}
else if(i == row - 1 && j == column - 1){
result[i][j] = 1;
}
else {
result[i][j] = result[i][j+1] + result[i+1][j];
}
}
}
return result[0][0];
}
}