118. Pascal's Triangle

 1 class Solution {
 2 public:
 3     vector<vector<int>> generate(int numRows) 
 4     {
 5         vector<vector<int>> pascal_triangle(numRows);
 6 
 7         if (numRows == 0)
 8         {
 9             return pascal_triangle;
10         }
11     
12         for (int i = 0; i < numRows; ++i)
13         {
14             pascal_triangle[i].push_back(1);
15 
16             for (int j = 1; j < i; ++j)
17             {
18                 pascal_triangle[i].push_back(pascal_triangle[i-1][j-1] + pascal_triangle[i-1][j]);
19             }
20 
21             if (i != 0)
22             {
23                 pascal_triangle[i].push_back(1);
24             }
25         }
26 
27         return pascal_triangle;
28     }
29 };