Follow up for "Unique Paths":
Now consider if some obstacles are added to the grids. How many unique paths would there be?
An obstacle 障碍 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.
class Solution {private:int b[101][101];public:int uniquePathsWithObstacles(vector<vector<int>>& a) {int i,j;int row=a.size();int col=a[0].size();b[0][0]= a[0][0]==1? 0:1;for(i=1;i<row;i++)b[i][0]= a[i][0]==1? 0:b[i-1][0];for(i=1;i<col;i++)b[0][i]= a[0][i]==1? 0:b[0][i-1];for(i=1;i<row;i++){for(j=1;j<col;j++){b[i][j]= a[i][j]==1? 0:b[i-1][j]+b[i][j-1];}}return b[row-1][col-1];}};
原文：http://www.cnblogs.com/zhoudayang/p/5013398.html