def METHOD_NAME(str_len: int, loc_list: List[int]) -> str:
    """
    This function returns a string of length str_len with 1s at the locations
    specified by loc_list and 0s elsewhere.
    Args:
        str_len: The length of the string.
        loc_list: A list of integers specifying the locations of 1s in the
            string.
    Returns:
        A string of length str_len with 1s at the locations specified by
        loc_list and 0s elsewhere.
        e.g. if str_len = 5, loc_list = [1,3], return '01010'
    """
    return "".join(
        map(lambda i: "1" if i in set(loc_list) else "0", range(str_len))
    )