"One Day together Leetcode" #63. Unique Paths II

One Day together Leetcode (i) Title

Follow up for "Unique Paths":

Now consider if some obstacles is added to the grids. How many unique paths would there be?

An obstacle and empty space are 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.

(ii) Problem solving

Problem-solving ideas: Refer to the previous blog post "One Day together Leetcode" #62. Unique Paths

classSolution { Public:intdp[101][101];intUniquepathswithobstacles ( vector<vector<int>>& Obstaclegrid) {introw = Obstaclegrid.size ();intCol =0;if(row!=0) col = obstaclegrid[0].size ();if(obstaclegrid[0][0]==1)return 0;//Starting point not to be returned directly 0         for(inti = row-1; i>=0; i--) for(intj = col-1; j>=0; j--) {if(obstaclegrid[i][j]==1) Dp[i][j] =0;//Representative blocked                Else if(i==row-1&&j==col-1) Dp[i][j] =1;//The DP at the specified end is 1                ElseDP[I][J] = dp[i+1][j]+dp[i][j+1]; }returndp[0][0]; }

"One Day together Leetcode" #63. Unique Paths II