A universal cycle for the k-permutations of n = {1, 2, ..., n} is a circular string of length nk that contains each k-permutation exactly once as a substring. Jackson (Discrete Mat...
Alexander E. Holroyd, Frank Ruskey, Aaron Williams
In the Imbalance Minimization problem we are given a graph G = (V, E) and an integer b and asked whether there is an ordering v1 . . . vn of V such that the sum of the imbalance of...