#
# Name: CS 111 Course Staff
#
# lab4task4.py
#

# helper function
def negate_if_even(val):
    """ input: a single integer val
        if val is even, the function returns -1 times val
        if val is odd, the function returns val without changing it
    """
    if val % 2 == 0:
        return -1 * val
    else:
        return val

def negate_evens_lc(vals):
    """ uses a list comprehension to return a version of the list vals 
        in which all even numbers have been multiplied by -1.
        input: vals is a list of arbitrary of integers
    """
    return [negate_if_even(x) for x in vals]