[LeetCode] Unique Paths 2
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) {
// Start typing your C/C++ solution below
// DO NOT write int main() function
int m=obstacleGrid.size();
int n=obstacleGrid[0].size();
vector<vector<int>> paths(m,vector<int>(n,0));
if(obstacleGrid.at(0).at(0)==1)
{
return 0;
}
else{
paths.at(0).at(0)=1;
}
for(int i=1;i<m;i++)
{
if(obstacleGrid.at(i).at(0)==0 && paths.at(i-1).at(0)==1)
paths.at(i).at(0)=1;
}
for(int i=1;i<n;i++)
{
if(obstacleGrid.at(0).at(i)==0 && paths.at(0).at(i-1)==1)
paths.at(0).at(i)=1;
}
for(int i=1;i<m;i++)
{
for(int j=1;j<n;j++)
{
if(obstacleGrid.at(i).at(j)==1)
paths.at(i).at(j)=0;
else
paths.at(i).at(j)=paths.at(i).at(j-1)+paths.at(i-1).at(j);
}
}
return paths.at(m-1).at(n-1);
}
};