def stretch_string(s: str, stretch_factors: List[int]) -> str:

"""Return a string consisting of the characters in s in the same order as in s, repeated the number of times indicated by the item at the corresponding position of stretch_factors.

Precondition: len(s) == len(stretch_factors) and the items of stretch_factors are non-negative

>>> stretch_string('Hello', [2, 0, 3, 1, 1])

'HHllllo'

"""