[LeetCode] 867. Transpose Matrix

Problem

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]]

Note:

1 <= A.length <= 1000
1 <= A[0].length <= 1000

Solution

class Solution {
    public int[][] transpose(int[][] A) {
        int m = A.length, n = A[0].length;
        int[][] B = new int[n][m];
        for (int j = 0; j < n; j++) {
            for (int i = 0; i < m; i++) {
                B[j][i] = A[i][j];
            }
        }
        return B;
    }
}