HMWK3

Due: 5 April 2018, by end of class

Take some time to examine some of the Ruby resources I've provided on the web page! 
Also, please just email your code to the grader to hand it in.  Easier for all.


1) Write a Ruby function which takes a list of integers, ignores the first three and then returns the sum of rest of the numbers.

2) Write a Ruby function which takes a single string and returns a string with only the odd (position) characters.

func("abcdef") => "ace"
func("hhiijjkk") => "hijk"

3) The following class definition is provided:

class Student
  def initialize
    @name = String.new()
    @age = Integer
    @id = Integer
    @grade = Integer
  end

  def this?(id)
    @id == id
  end

  def name()
    @name
  end

  def name=(name)
     @name=name
  end

  def age=(age)
     @age=age
  end

  def id=(id)
     @id = id
  end

  def grade()
     @grade
  end

  def grade=(grade)
     @grade=grade
  end
end


Write a class which stores a collection of students.  
It should implement the following four functions:

add(string,int,int,int) puts a new student record in the structure
find(int) returns the name (or error string) of the student with them matching id
top() returns the name of the student with the highest grade
median() returns the median age of the students