LeetCode 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.

class Solution {public:int uniquePathsWithObstacles(vector<vector<int> > &obstacleGrid) {unsigned m = obstacleGrid.size();unsigned n = obstacleGrid[0].size();if (m == 0 || n == 0)return 0;vector<vector<int> > array(m, vector<int>(n, 1));for (int i = 0; i < m; ++i) {if (obstacleGrid[i][0] == 1) {for (int j = i; j < m; ++j)array[j][0] = 0;break;}}for (int i = 0; i < n; ++i) {if (obstacleGrid[0][i] == 1) {for (int j = i; j < n; ++j)array[0][j] = 0;break;}}for (int i = 1; i < m; ++i) {for (int j = 1; j < n; ++j) {if (obstacleGrid[i][j] == 1)array[i][j] = 0;else array[i][j] = array[i][j - 1] + array[i - 1][j];}}return array[m - 1][n - 1];}};