Track Median : Utility Method « Method « Ruby

1. Ruby
2. Method
3. Utility Method

Track Median

 
def mean(array)
  array.inject(0) { |sum, x| sum += x } / array.size.to_f
end

 
def median(array, already_sorted=false)
  return nil if array.empty?
  array = array.sort unless already_sorted
  m_pos = array.size / 2
  return array.size % 2 == 1 ? array[m_pos] : mean(array[m_pos-1..m_pos])
end

puts median([1,2,3,4,5])                             # => 3
puts median([5,3,2,1,4])                             # => 3
puts median([1,2,3,4])                               # => 2.5
puts median([1,1,2,3,4])                             # => 2
puts median([2,3,-100,100])                          # => 2.5
puts median([1, 1, 10, 100, 1000])                   # => 10

 

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