题目:
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.
思路:对于有障碍的坐标,将到达这个位置的路数标记为0即可
#include <iostream>
#include <vector>
using namespace std;
int UniquePath(int m,int n,int line ,int row)
{
int i,j;
vector<vector<int> > path;
for(i=0;i<m;i++)
{
vector<int> vec(n,0);
path.push_back(vec);
}
for(i=0;i<m;i++)
path[i][0] = 1;
for(i=0;i<n;i++)
path[0][i] = 1;
for(i=1;i<m;i++)
for(j=1;j<path[0].size();j++)
if(i ==line && j == row)
path[i][j] = 0;
else
path[i][j] = path[i-1][j] +path[i][j-1];
for(i=0;i<m;i++)
{
for(j=0;j<path[0].size();j++)
cout<<path[i][j]<<" ";
cout<<endl;
}
return path[m-1][n-1];
}
int main()
{
cout<<UniquePath(3,3,1,1)<<endl;
return 0;
}
这里需要注意的那个障碍的点是按照一个标准数组的位置来说的。