rotate_matrix.py

# Problem: Rotate a square matrix by
# 90 degree with O(1) extra space
def rotate_by_90(m):
    # unpacking arguments with zip(*) in reverse with [ : :-1]
    tuples = zip(*m[::-1])
    # flattening tuples to list with [list(i)]
    return [list(i) for i in tuples]


def makeMatrix(array, size):
    # validating size of matrix for given array
    if size ** 2 != len(array):
        return -1
    # make sub array of length size using array slicing
    else:
        matrix = [array[i : i + size] for i in range(0, len(array), size)]
        return rotate_by_90(matrix)


arr = [1, 2, 3, 4]
dimension = 2
result = makeMatrix(arr, dimension)
# Original Matrix: [[1, 2], [3, 4]]
# Result: [[3, 1], [4, 2]]