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