解题思路

动态规划

  public int uniquePathsWithObstacles(int[][] obstacleGrid) {
        int R = obstacleGrid.length;
        int C = obstacleGrid[0].length;
        //特判
        if (obstacleGrid[0][0] == 1)
            return 0;
        obstacleGrid[0][0] = 1;
        //对第一列进行判断
        for (int i = 1;i < R;i++){
            obstacleGrid[i][0] = (obstacleGrid[i][0] == 0 && obstacleGrid[i-1][0] == 1) ?1:0;
        }
        //对第一行进行判断
        for(int j = 1;j < C;j++){
            obstacleGrid[0][j] = (obstacleGrid[0][j] == 0 && obstacleGrid[0][j-1] == 1) ? 1:0;
        }
        for (int i = 1;i < R;i++){
            for (int j = 1;j < C;j++){
                if (obstacleGrid[i][j] == 0)
                    obstacleGrid[i][j] = obstacleGrid[i-1][j] + obstacleGrid[i][j-1];
                else
                    obstacleGrid[i][j] = 0;
            }
        }
        return obstacleGrid[R-1][C-1];
    }