118. Pascal's Triangle (Array)

Given numRows, generate the first numRows of Pascal's triangle.

For example, given numRows = 5,
Return

[
     [1],
    [1,1],
   [1,2,1],
  [1,3,3,1],
 [1,4,6,4,1]
]

 

 

class Solution {
public:
    vector<vector<int> > generate(int numRows) {
        vector<vector<int>> result(numRows, vector<int>());
        if(numRows == 0) return result;
        result[0].push_back(1);
        for(int i =1; i < numRows; i++) 
        {
            result[i].push_back(1);
            for(int j = 1; j<i;j++) 
            {
                result[i].push_back(result[i-1][j-1]+result[i-1][j]);
            }
            result[i].push_back(1);
        }
        return result;
    }
};