Interview Question

Software Engineer Interview

Write an algorithm that tells me if 2 and only two numbers

  in a 1x3 array are the same.
Answer

Interview Answer

1 Answer

0

In ruby:

def find_it(arr)
    a = Hash.new(0)
    arr.each do |b|
      a[b] += 1
  end

  a.each do |k, v|
    return true if v == 2
  end

  return false
end

That will find two and only two matches in an arbitrarily long array. For extra credit, how can you optimize it for an array of only 3 elements?

Renski on Apr 20, 2013

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