Lecture 12: Midterm Review

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Lecture 12 Midterm Review

• Multiple choice quiz from pub website (see web
  page for link and use access code liang6e614 )
• Homework 5 N Queens
• Sample midterm questions

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Sample Question 1

• Write a method
• public static String reverse(String s)
• that returns the reverse of s. Use a loop and
  the length() and charAt() methods from the String
  class. Do not use recursion. Make sure your
  method works if s is the empty string.

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Sample Question 2

• Write a method
• public static String reverse(String s)
• that, as in Question 1, returns the reverse of s,
  but instead of using a loop, use recursion. Use
  the charAt and substring methods. Note that, for
  example, if s is abcdef, then s.substring(2,4)
  is cd. Make sure your method works if s is the
  empty string.

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Sample Question 3

• Write a method
• public int getEvenHalf(int x)
• that returns a new array consisting of every
  second element of x. It should work whether the
  length of x is even or odd, including length 0
  (the empty array).
• For example, if the elements of x are 1 2 3 6 7 8
  9 the method should return a new array with
  elements 1 3 7 9.
• The method should not change the array x.
• Remember that x.length is a data field, not a
  method.
• Also write a snippet of code that constructs a
  random int array and calls getEvenHalf.

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Sample Question 4

• Write a method equals for our Date class of
  Homework 4 in such a way that it overrides the
  equals method of the Object class.
• Give an example of a snippet of code that calls
  this method for which it is important to
  implement the Date equals method in this way, as
  opposed to the way you wrote it in Homework 4,
  which did not override the equals method of the
  Object class.