Pascal's Triangle
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>> ans; for(int i = 0; i<numRows; i++){ vector<int> cur; if(i == 0) cur.push_back(1); else{ for(int j = 0; j<=i; j++){ if(j == 0 || j == i) cur.push_back(1); else cur.push_back(ans[i-1][j-1]+ans[i-1][j]); } } ans.push_back(cur); } return ans; } };