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) {

        // Start typing your C/C++ solution below

        // DO NOT write int main() function

        vector<vector<int>> result;

        if(numRows <= ) return result;

        vector<int> first;

        first.push_back(); result.push_back(first);

        for(int i = ; i < numRows ; i++)

        {

            vector<int> temp(i+);

            for(int j =  ; j < i+ ; j++){

                if( j ==  || j == i){

                    temp[j] = ;continue;

                }else{

                    temp[j] = result[i-][j] + result[i-][j-] ;

                    continue;

                }

            }

            result.push_back(temp);

        }

        return result ;

    }

};