Leetcode#63||Unique Paths II

public class Solution {
public int uniquePathsWithObstacles(int[][] obstacleGrid) {
if (obstacleGrid == null || obstacleGrid.length == 0 || obstacleGrid[0].length ==0) {
return 0;
}

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

int[] paths = new int
;

for (int j = 0; j < n; j++) {
if (obstacleGrid[0][j] == 0) {
paths[j] = 1;
} else if (obstacleGrid[0][j] == 1) {
break;
}
}

for (int i = 1; i < m; i++) {
if (obstacleGrid[i][0] == 1) {
paths[0] = 0;
}

for (int j = 1; j < n; j++) {
if (obstacleGrid[i][j] == 1) {
paths[j] = 0;
} else {
paths[j] += paths[j - 1];
}
}
}

return paths[n - 1];
}
}