from typing import List


def isPermutation(L: List[int]) -> bool:
    """Returns True if L is a permutation of the integers from 0 to len(L)-1."""
    return sorted(L) == list(range(len(L)))


def testIsPermutation():
    print("Testing isPermutation()...", end="")
    assert isPermutation([0, 2, 1, 4, 3]) == True
    assert isPermutation([1, 3, 0, 4, 2]) == True
    assert isPermutation([1, 3, 5, 4, 2]) == False
    assert isPermutation([1, 4, 0, 4, 2]) == False

    # Verify that the function is nonmutating:
    L = [0, 2, 1, 4, 3]
    isPermutation(L)
    assert L == [0, 2, 1, 4, 3]
    print("Passed!")


def main():
    testIsPermutation()


main()