Unique Paths II （dp题）

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.

代码：

class Solution {

public:

    int uniquePathsWithObstacles(vector<vector<int> > &obstacleGrid) {

          if(obstacleGrid.size()==) return ;

          int row=obstacleGrid.size();

          int col=obstacleGrid[].size();

          int dp[][];

          memset(dp,,sizeof(dp));

          bool rblockTag=false;

          bool cblockTag=false;

          if(obstacleGrid[][]==||obstacleGrid[row-][col-]==)

            return ;

          for(int i=;i<col;++i){

              if(obstacleGrid[][i]==) rblockTag=true;

              if(!rblockTag) dp[][i]=;

              else dp[][i]=;

          }

          for(int j=;j<row;++j){

              if(obstacleGrid[j][]==) cblockTag=true;

              if(!cblockTag) dp[j][]=;

              else dp[j][]=;

          }

          for(int i=;i<row;++i){

              for(int j=;j<col;++j){

                  if(obstacleGrid[i][j]==) dp[i][j]=;

                  else dp[i][j]=dp[i][j-]+dp[i-][j];//i和j是从1开始

              }

          }

          return dp[row-][col-];

      }

};

巴特西

Unique Paths II （dp题）

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