Finding two non-subsequent elements in array which sum is minimal

Question

Intro: As far as I could search, this question wasn\'t asked in SO yet.
This is an interview question.
I am not even specifically looking for a code sol

Answer 1

1. Find the smallest number beside the first and the last.

2. Find the second smallest that is not a neighbour of the first one and not the first or last one in the array. Then build the sum.

   • If the first element is the second or the penultimate element you already have the solution.

3. Otherwise calculate the sum of both neighbours of the first number. check if its smaller then the first sum

   • if not: take the first sum
   • otherwise take the second one

This will always work because if the first sum is not the answer that means the first number cannot be part of the solution. And that on the other hand means, the solution can just be the second sum.