Pascal's Triangle II 杨辉三角

 1 class Solution {
 2 public:
 3     vector<int> getRow(int rowIndex) {
 4         vector<vector<int>> tri;
 5         if(rowIndex==0)
 6         {
 7             vector<int> c;
 8             c.push_back(1);
 9             return c;
10         }
11         vector<int> b;
12         b.push_back(0);
13         b.push_back(1);
14         b.push_back(0);
15         tri.push_back(b);
16         
17         for(int i=1;i<=rowIndex;i++)
18         {
19             vector<int> a;
20             a.push_back(0);
21             for(int j=1;j<=i+1;j++)
22                 a.push_back(tri[i-1][j-1]+tri[i-1][j]);
23             a.push_back(0);
24             tri.push_back(a);
25         }
26         vector<int> res;
27         for(int i=1;i<=rowIndex+1;i++)
28         {
29             res.push_back(tri[rowIndex][i]);
30         }
31         
32         return res;
33         
34     }
35 };