Subtask 1

For the first subtask, you can just brute force all possible ways you can visit all the houses and output any that matches the constraints of the problem.

Time Complexity: ~\mathcal{O}(N! \cdot N)~

Subtask 2

The trick here is to start from ~1~, then go to ~N~, then back to ~2~, then go to ~N-1~, then back to ~3~, etc. If you look at the sequence here, you'll notice the absolute difference between adjacent values is constantly decreasing:

$$\displaystyle 1,N,2,N-1,3,N-2,\dots$$

Absolute Value of Differences:

$$\displaystyle N-1,N-2,N-3,N-4,N-5,\dots$$

Time Complexity: ~\mathcal{O}(N)~