Loot on a Ring Road — Solution & Editorial
Either house 1 is skipped or house N is skipped: run the linear DP on a[2..N] and a[1..N−1] and take the better.
Complexity: O(N)
Either house 1 is skipped or house N is skipped: run the linear DP on a[2..N] and a[1..N−1] and take the better.
Complexity: O(N)