leetcode@ [62/63] Unique Paths II

 class Solution {

 public:

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

         if(obstacleGrid.size()== || obstacleGrid[].size()==) return ;

         int m = obstacleGrid.size(), n = obstacleGrid[].size();

         if(obstacleGrid[m-][n-]==) return ;

         vector<vector<int> > dp(m);

         for(int i=;i<dp.size();++i) dp[i].resize(n);

         for(int i=;i<dp.size();++i){

             for(int j=;j<dp[i].size();++j) dp[i][j]=;

         }

         dp[][] = (obstacleGrid[][]==) ?  : ;

         for(int i=;i<dp.size();++i){

             if(dp[i-][] && !obstacleGrid[i][]) dp[i][] = ;

         }

         for(int j=;j<dp[].size();++j){

             if(dp[][j-] && !obstacleGrid[][j]) dp[][j] = ;

         }

         for(int i=;i<dp.size();++i){

             for(int j=;j<dp[i].size();++j){

                 if(i>= && !obstacleGrid[i-][j]) dp[i][j] += dp[i-][j];

                 if(j>= && !obstacleGrid[i][j-]) dp[i][j] += dp[i][j-];

             }

         }

         return dp[m-][n-];

     }

 };