Pascal's Triangle II

 1   vector<int> getRow(int rowIndex) {
 2         vector<int>lastRow;
 3         vector<int>cur;
 4         
 5         if (rowIndex >= 0)
 6         {
 7             cur.push_back(1);
 8             lastRow = cur;
 9             
10             for (int i = 1; i <= rowIndex; ++i)
11             {
12                 cur.clear();
13                 for (int j = 0; j <= i; ++j)
14                 {
15                     if (j == 0)
16                         cur.push_back(lastRow[0]);
17                     else if (j==lastRow.size())
18                         cur.push_back(lastRow[j-1]);
19                     else
20                         cur.push_back(lastRow[j]+lastRow[j-1]);
21                 }
22                 lastRow = cur;
23             }
24         }
25         return lastRow;
26     }