from typing import List


def mutatingInsertRowAndCol(L: List[List[int]], row: int, col: int, val: int):
    """Inserts a row and column into a matrix."""
    L.insert(row, [val] * len(L[0]))
    for i in range(len(L)):
        L[i].insert(col, val)


def nonmutatingInsertRowAndCol(
    L: List[List[int]], row: int, col: int, val: int
) -> List[List[int]]:
    """Inserts a row and column into a matrix without mutating the original matrix."""
    new_list = [[v for v in l] for l in L]

    new_list.insert(row, [val] * len(new_list[0]))
    for i in range(len(new_list)):
        new_list[i].insert(col, val)

    return new_list


def testMutatingInsertRowAndCol():
    print("Testing mutatingInsertRowAndCol()...", end="")
    L = [[1, 2, 3, 4], [5, 6, 7, 8], [9, 10, 11, 12]]
    mutatingInsertRowAndCol(L, 1, 2, 42)
    assert L == [
        [1, 2, 42, 3, 4],
        [42, 42, 42, 42, 42],
        [5, 6, 42, 7, 8],
        [9, 10, 42, 11, 12],
    ]

    L = [[1, 2, 3], [4, 5, 6]]
    mutatingInsertRowAndCol(L, 0, 0, 5)
    assert L == [[5, 5, 5, 5], [5, 1, 2, 3], [5, 4, 5, 6]]

    L = [[1, 2, 3], [4, 5, 6]]
    mutatingInsertRowAndCol(L, 1, 3, 5)
    assert L == [[1, 2, 3, 5], [5, 5, 5, 5], [4, 5, 6, 5]]


def testNonmutatingInsertRowAndCol():
    print("Testing nonmutatingInsertRowAndCol()...", end="")
    L = [[1, 2, 3, 4], [5, 6, 7, 8], [9, 10, 11, 12]]
    assert nonmutatingInsertRowAndCol(L, 1, 2, 42) == [
        [1, 2, 42, 3, 4],
        [42, 42, 42, 42, 42],
        [5, 6, 42, 7, 8],
        [9, 10, 42, 11, 12],
    ]

    L = [[1, 2, 3], [4, 5, 6]]
    assert nonmutatingInsertRowAndCol(L, 0, 0, 5) == [
        [5, 5, 5, 5],
        [5, 1, 2, 3],
        [5, 4, 5, 6],
    ]

    L = [[1, 2, 3], [4, 5, 6]]
    assert nonmutatingInsertRowAndCol(L, 1, 3, 5) == [
        [1, 2, 3, 5],
        [5, 5, 5, 5],
        [4, 5, 6, 5],
    ]

    # Verify that the function is non-mutating
    L = [[1, 2, 3, 4], [5, 6, 7, 8], [9, 10, 11, 12]]
    nonmutatingInsertRowAndCol(L, 1, 2, 42)
    assert L == [[1, 2, 3, 4], [5, 6, 7, 8], [9, 10, 11, 12]]
    print("Passed!")


def main():
    testMutatingInsertRowAndCol()
    testNonmutatingInsertRowAndCol()


main()