carolineartz
1/12/2014 - 4:15 AM

Exercise: Calculating the median of an array of numbers Write a method median which takes an Array of numbers as its input and returns the

Exercise: Calculating the median of an array of numbers Write a method median which takes an Array of numbers as its input and returns the median value.

challenge1_1_array_median.rb
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# CALCULATE THE MEDIAN OF AN ARRAY OF NUMBERS
# PSEUDOCODE 
# INPUT: array of numbers 
# OUPUT: the median number of the elements of the input array
# STEPS: sort the array 
# determine if the array has one or two middle values by checking
# if the length is even or odd
# if there is an odd length, return the value of the middle element
# otherwise return the average of the two middle elements' values

# INITIAL CODE:
def median(array)
  array.sort!
  n = array.length
  if n % 2 != 0
    return array[(n - 1) / 2]
  else
    return (array[n/2] + array[(n/2)-1]) / 2.0
  end
end

# REFACTORED CODE:
def median(array)
  mid = array.length / 2

  if array.length.odd?
    array.sort![mid]
  else
    (array.sort![mid - 1] + array[mid]) / 2.0
  end
end


# REVIEW/REFLECT  My approach for this problem was pretty solid, I believe. I
# can't figure out much more to refactor; most solutions I have found within
# DBC and outside have pretty simliar logic and use of methods. I did find out
# about this little #odd? method, and its complement #even?, and now I can
# avoid using the modulus technique for testing even/odd. I'll have to
# remember these!