puzzles.md

puzzle 01

# Description: 
# given a list of integer(no duplicate), find all pairs that add up to a target number
# example: list=[1,3,5,7] target=8, result = 1,7 3,5
# requirement: as fast as possible
require 'set'

def find_pair(ary, sum)
  res = []
  s = Set.new()
  ary.each {|x|
    left = sum - x
    if s.include?(left)
      res.push(Set.new([x, left]))
      s.delete(left)
    else
      s.add(x)
    end
  }

  return res
end

puts find_pair([1, 2 ,3, 6, 4, 8], 9)