LeetCode 867. 转置矩阵

示例 1：
输入：[[1,2,3],[4,5,6],[7,8,9]]
输出：[[1,4,7],[2,5,8],[3,6,9]]

示例 2：
输入：[[1,2,3],[4,5,6]]
输出：[[1,4],[2,5],[3,6]]
 
提示：
1 <= A.length <= 1000
1 <= A[0].length <= 1000

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

class Solution {
public:
    vector<vector<int>> transpose(vector<vector<int>>& A) {
        int i, j, x, y = 0, m = A.size(), n = A[0].size();
        vector<vector<int>> ans(n,vector<int>(m));
        for(i = 0; i < m; ++i)
        {
            x = 0;
            for(j = 0; j < n; ++j)
            {
                ans[x++][y] = A[i][j];
            }
            y++;
        }
        return ans;
    }
};