https://community.topcoder.com/stat?c=problem_statement&pm=2402&rd=5009

BadNeighbours.py

class BadNeighbours:

    def maxDonations(self, donations):
        L = len(donations)
        if L < 3:
            return max(donations)

        # memo1[L-2] will have maximum value of donations which
        # *may* include the first neighbour (therefore cannot include
        # the last neighbour)
        # memo2[L-1] will have the maximum value of donations
        # which do not include the first neighbour (and therefore
        # can include the last neighbour)
        memo1, memo2 = [0]*L, [0]*L

        memo1[0], memo2[0] = donations[0], 0
        memo1[1], memo2[1] = donations[1], donations[1]
        memo1[2], memo2[2] = donations[2] + memo1[0], donations[2] + memo2[0]

        for n in range(3, L):
            memo1[n] = max(memo1[n-2] + donations[n], memo1[n-3] + donations[n])
            memo2[n] = max(memo2[n-2] + donations[n], memo2[n-3] + donations[n])

        return max(memo1[L-2], memo2[L-1])