indexOf

Write a static method indexOf that takes two
    arrays of integers and that returns the index of the first occurrence of
    the first list in the second list or -1 if the first list does not appear
    in the second list.  For example, suppose that you have two integer arrays
    called list1 and list2 that store the following values:

        list1: (1, 3, 5, 8, 12, 1, 3, 17, 1, 3, 6, 9, 1, 3, 6)
	list2: (1, 3, 6)

    then the call:

        indexOf(list2, list1)

    should return 8 because the sequence of values stored in list2 appears in
    list1 starting with index 8.  Notice that list2 actually appears twice in
    list1, starting at position 8 and starting at position 12.  Your method is
    to return the first such position.

    If the second list is not contained in the first list, then the method
    should return the value -1.  For example, if list1 had the same value as
    before but list2 stored (12, 1, 3, 6), then the call indexOf(list2, list1)
    should return -1 because list2 is not contained in list1.  If the first
    list is empty, your method should return 0.

    Write your solution to indexOf below.