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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def find_share_ring(self, tree_map, parent_map, r):
 """ get a ring structure that tends to share nodes with the tree return a list starting from r """

        nset = set(tree_map[r])
        cset = nset - set([parent_map[r]])
        if len(cset) == 0:
            return [r]
        rlst = [r]
        cnt = 0
        for v in cset:
            vlst = self.find_share_ring(tree_map, parent_map, v)
            cnt += 1
            if cnt == len(cset):
                vlst.reverse()
            rlst += vlst
        return rlst