开始刷leetcode day60: 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.

Note: m and n will be at most 100.

Java:

public class Solution {
    public int uniquePathsWithObstacles(int[][] obstacleGrid) {
        if(obstacleGrid == null) return 0;
        int row = obstacleGrid.length;
        int col = obstacleGrid[0].length;
        
        
        int[][] destination = new int[row][col];
        if(obstacleGrid[0][0]==1) return 0;
        destination[0][0] = 1;
        for(int i=1; i<row; i++)
        {
            if(destination[i-1][0] != 0 && obstacleGrid[i][0] != 1) destination[i][0] = 1;
            else    destination[i][0] = 0;
        }
        
        for(int j=1; j<col; j++)
        {
            if(destination[0][j-1]!=0 && obstacleGrid[0][j] != 1) destination[0][j] = 1;
            else destination[0][j] = 0;
        }
        
        for(int i=1; i<row; i++)
        {
            for(int j=1; j<col; j++)
            {
                if(obstacleGrid[i][j] == 1) destination[i][j] = 0;
                else    destination[i][j] = destination[i-1][j] + destination[i][j-1];
            }
        }
        
        
        return destination[row-1][col-1];
    }
}