class Solution {public:    vector
     
       getRow(int rowIndex) {       vector
      
        result;       int i = 0;       int j = 0;       if(rowIndex < 0) {           return result;       }              result.push_back(1);       if(rowIndex == 0){           return result;       }              for(i = 1; i <= rowIndex; i++){           for(j = result.size() - 1; j > 0; j--){//注意。此处不能够写成for(j =1; j j