# LeetCode 867. Transpose Matrix

## Description

https://leetcode.com/problems/transpose-matrix/

Given a 2D integer array `matrix`, return the transpose of `matrix`.

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

Example 1:

```Input: matrix = [[1,2,3],[4,5,6],[7,8,9]]
Output: [[1,4,7],[2,5,8],[3,6,9]]
```

Example 2:

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

Constraints:

• `m == matrix.length`
• `n == matrix[i].length`
• `1 <= m, n <= 1000`
• `1 <= m * n <= 105`
• `-109 <= matrix[i][j] <= 109`

## Explanation

Simply assign matrix[i][j] value to the transpose matrix[j][i] cell.

## Python Solution

``````class Solution:
def transpose(self, matrix: List[List[int]]) -> List[List[int]]:
transpose_matrix = [[0 for i in range(0, len(matrix))] for j in range(0, len(matrix))]

for i in range(0, len(matrix)):
for j in range(0, len(matrix)):
transpose_matrix[j][i] = matrix[i][j]

return transpose_matrix
``````
• Time Complexity: O(MN).
• Space Complexity: O(MN).