Three Sum

Find all unique triplets in an array that sum to a target value.

Code

Algorithms

a = arr.sort
result = []
(0...a.length - 2).each do |i|
  next if i > 0 && a[i] == a[i - 1]
  l, r = i + 1, a.length - 1
  while l < r
    s = a[i] + a[l] + a[r]
    if s == target
      result << [a[i], a[l], a[r]]
      l += 1 while l < r && a[l] == a[l + 1]
      r -= 1 while l < r && a[r] == a[r - 1]
      l += 1; r -= 1
    elsif s < target then l += 1
    else r -= 1
    end
  end
end
return result

Parameters

arr(array)

Array of numbers

target(number)

Target sum

Server

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