The srand function uses the argument as a seed for a new sequence
    of pseudorandom numbers to be returned by subsequent calls to
    rand.

    If srand is then called with the same seed value, the sequence of
    pseudorandom numbers is repeated.

    If rand is called before any calls to srand, the same sequence of
    pseudorandom numbers is generated as when srand is first called
    with a seed value of 1.