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 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
Solutions
1. Array - Direct
# Time: O(mn)
# Space: O(n)
class Solution:
def transpose(self, A: List[List[int]]) -> List[List[int]]:
if not A:
return []
row, col = len(A), len(A[0])
res = []
for c in range(col):
cols = []
for r in range(row):
cols.append(A[r][c])
res.append(cols)
return res
# 36/36 cases passed (76 ms)
# Your runtime beats 56.02 % of python3 submissions
# Your memory usage beats 100 % of python3 submissions (13.5 MB)