I received a pre-screen 3 business days after applying.

Front-End Development Framework:

This is an exercise of 1 hour. You need to solve a question similar to those on LeetCode. They use CodeSignal. After passing the pre-screen, there is a technical interview. The most qualified applicants will be called for a personality profile type interview.

Let's say a triple (a, b, c) is a zigzag if either a < b > c or a > b < c.

Given an array of integers numbers, your task is to check all the triples of its consecutive elements for being a zigzag. More formally, your task is to construct an array of length numbers.length - 2, where the ith element of the output array equals 1 if the triple (numbers[i], numbers[i + 1], numbers[i + 2]) is a zigzag, and 0 otherwise.

Example:

• For numbers = [1, 2, 1, 3, 4], the output should be solution(numbers) = [1, 1, 0].

  • (numbers[0], numbers[1], numbers[2]) = (1, 2, 1) is a zigzag, because 1 < 2 > 1;
  • (numbers[1], numbers[2], numbers[3]) = (2, 1, 3) is a zigzag, because 2 > 1 < 3;
  • (numbers[2], numbers[3], numbers[4]) = (1, 3, 4) is not a zigzag, because 1 < 3 < 4;

• For numbers = [1, 2, 3, 4], the output should be solution(numbers) = [0, 0]. Since all the elements of numbers are increasing, there are no zigzags.

• For numbers = [1000000000, 1000000000, 1000000000], the output should be solution(numbers) = [0]. Since all the elements of numbers are the same, there are no zigzags.