867 Transpose Matrix 转置矩阵
Description:
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:
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]]
Note:
1 <= A.length <= 1000
1 <= A[0].length <= 1000
题目描述:
给定一个矩阵 A， 返回 A 的转置矩阵。
矩阵的转置是指将矩阵的主对角线翻转，交换矩阵的行索引与列索引。
示例 :
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
思路:
复制到新的空间即可
时间复杂度O(nm), 空间复杂度O(1)
代码:
C++:
class Solution
{
public:
vector<vector<int>> transpose(vector<vector<int>>& A)
{
vector<vector<int>> result(A[0].size(), vector<int>(A.size(), 0));
for (int i = 0; i < A[0].size(); i++) for (int j = 0; j < A.size(); j++) result[i][j] = A[j][i];
return result;
}
};
Java:
class Solution {
public int[][] transpose(int[][] A) {
int result[][] = new int[A[0].length][A.length];
for (int i = 0; i < A[0].length; i++) for (int j = 0; j < A.length; j++) result[i][j] = A[j][i];
return result;
}
}
Python:
class Solution:
def transpose(self, A: List[List[int]]) -> List[List[int]]:
return [list(i) for i in zip(*A)]
