leetcode 63

https://leetcode.com/problems/unique-paths-ii/description/

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.

我的代码排名70%

/**
 * @param {number[][]} obstacleGrid
 * @return {number}
 */
var uniquePathsWithObstacles = function(obstacleGrid) {


    n=obstacleGrid.length;
    m=obstacleGrid[0].length;


    if(obstacleGrid[0][0]==1 || obstacleGrid[n-1][m-1]==1 ){
        return 0;
    }
    for(var i=0;i<n;i++){
        for(var j=0;j<m;j++){
            if(i==0 || j==0 ){
                if(obstacleGrid[i][j]!=1) {
                    if (i == 0 && j > 0 && ( obstacleGrid[i][j - 1] == 1 || obstacleGrid[i][j - 1] == 0) ) {
                        obstacleGrid[i][j] = 0;


                    } else if (j == 0 && i > 0 && ( obstacleGrid[i - 1][j] == 1 || obstacleGrid[i-1][j ] == 0) ){
                        obstacleGrid[i][j] = 0;


                    } else{
                        obstacleGrid[i][j] = -1;
                    }
                }
            }else{
                if(obstacleGrid[i][j]!=1){
                    obstacleGrid[i][j]=(obstacleGrid[i-1][j]==1?0:obstacleGrid[i-1][j])+(obstacleGrid[i][j-1]==1?0:obstacleGrid[i][j-1]);
                }
            }
        }
    }
    return Math.abs(obstacleGrid[i-1][j-1]==1?0:-obstacleGrid[i-1][j-1]);
};