CSE341 Section #2 Problems

1. Write a function called twoSame that returns true if a list of values has
   two consecutive values that are equal.  Use pattern matching rather than
   calling functions like length, hd, and tl.

2. Write a function called stutter that takes a list as an argument and that
   returns the list formed by replacing each value in the list with two of that
   value.  For example, stutter([1, 2, 3]) should return [1, 1, 2, 2, 3, 3].

3. Write a function called stutterString that returns the result of replacing
   each character of a string with two of that character.  For example,
   stutterString("hello") should return "hheelloo".

4. Write a function isPrime that takes an integer n and that returns true if n
   is a prime and false if it is not.  By definition, a number is prime if it
   is divisible only by itself and 1.  Your function should return false when n
   is less than 2.

5. Consider the following attempt to compute the maximum value in a list:
        fun bad_max([x]) = x
        |   bad_max(x::xs) =
                if x > bad_max(xs) then x
                else bad_max(xs)
   What is the complexity of this function?  Rewrite it to be O(n).

6. Write a function cycle that takes an integer n and a list and that returns
   the list obtained by moving the first n values to the end of the list.  For
   example, cycle(4, [1, 2, 3, 4, 5, 6]) should return [5, 6, 1, 2, 3, 4].  You
   may assume that n is less than or equal to the length of the list.  For this
   function, you can cycle a single value to the end of the list n different
   times.

7. Write a variation of the function described in problem 5 called cycle2 that
   computes its result efficiently.  In particular, it should only perform a
   single list append.  You may call the built-in function rev which is an
   efficient implementation of the reverse operation.