#include <vector>

using namespace std;

class Solution {

public:

vector<vector<int> > generate(int numRows) {

std::vector<std::vector<int> > result;

for (int i=0; i<numRows; i++) {

std::vector<int> v(i+1);

v[0] = v[i] = 1;

for (int j=1; j<i; j++) {

v[j] = result[i-1][j-1] + result[i-1][j];

}

result.push_back(v);

}

return result;

}

};