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) { int rows = obstacleGrid.size(); if(rows<1) return rows; int cols = obstacleGrid[0].size(); if(cols<1) return cols; vector<int> temp(cols,1); vector<vector<int> > res(rows,temp);//res记录到达相应位置的路径条数 for(int i = 0;i<rows;i++){ for(int j=0;j<cols;j++){ if(obstacleGrid[i][j]==1) res[i][j] = 0; else if(i==0 && j!=0) res[i][j] = res[i][j-1]; else if(j==0 && i!=0) res[i][j] = res[i-1][j]; else if(i!=0 && j!=0) res[i][j] = res[i-1][j]+res[i][j-1]; } }//end for return res[rows-1][cols-1]; } };
[LeetCode] Unique Paths II(DP),布布扣,bubuko.com
[LeetCode] Unique Paths II(DP)
原文：http://www.cnblogs.com/Xylophone/p/3892414.html