# [leetcode] Unique Paths II

### 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 3×3 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.

int map = {0};不能将所有元素初始化，需要一个循环来初始化。

```class Solution {
public:
int uniquePathsWithObstacles(vector<vector<int> > &obstacleGrid) {
if(obstacleGrid.empty()) return 0;
int height = obstacleGrid.size();
int length = obstacleGrid.size();
if(height == 0 || length == 0) return 0;
int map[height + 1][length + 1];
for(int i = 0; i < height + 1; i++){
for(int j = 0; j < length + 1; j++){
map[i][j] = 0;
}
}
for(int i = 1; i <= height; i++){
for(int j = 1; j <= length; j++){
if(obstacleGrid[i - 1][j - 1] == 1){
map[i][j] = 0;
}
else if(i == 1 && j == 1){
map[i][j] = 1;
}
else{
map[i][j] = map[i-1][j] + map[i][j-1];
}
}
}
return map[height][length];
}
};``` This site uses Akismet to reduce spam. Learn how your comment data is processed.