Given a matrix A, return the transpose of A.

The transpose of a matrix is the matrix flipped over it's main diagonal, switching the row and column indices of the matrix.

 

Example 1:

Input: [[1,2,3],[4,5,6],[7,8,9]]
Output: [[1,4,7],[2,5,8],[3,6,9]]
Example 2:

Input: [[1,2,3],[4,5,6]]
Output: [[1,4],[2,5],[3,6]]

class Solution {
public:
	vector<vector<int>> transpose(vector<vector<int>>& A) {
		vector<vector<int>> res;
		vector<int> t;
		if (A.size() == 0 || A[0].size() == 0) {
			return res;
		}
		for (int i = 0; i < A[0].size(); i++) {
			t.clear();
			for (int j = 0; j < A.size(); j++) {
				t.push_back(A[j][i]);
			}
			res.push_back(t);
		}
		return res;
	}
};