[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 <= 10001 <= 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;
}
}