动态规划9（Leetcode63不同路径2）

代码：

class Solution {
    public int uniquePathsWithObstacles(int[][] obstacleGrid) {
        int m = obstacleGrid.length;
        int n = obstacleGrid[0].length;
        int[][] pathNum = new int[m][n];
        if(obstacleGrid[0][0]==1)return 0;
        pathNum[0][0] = 1;
        for(int i=1;i
            if(obstacleGrid[i][0]==1)pathNum[i][0]=0;
            else pathNum[i][0] = pathNum[i-1][0];
        }
        for(int i=1;i
            if(obstacleGrid[0][i]==1)pathNum[0][i]=0;
            else pathNum[0][i] = pathNum[0][i-1];
        }
        for(int i=1;i
            for(int j=1;j
                if(obstacleGrid[i][j]==1)pathNum[i][j]=0;
                else pathNum[i][j] = pathNum[i-1][j]+pathNum[i][j-1];
            }
        }
        return pathNum[m-1][n-1];
 
    }
}