Prefix exchanging and pattern avoidance by involutions.
Primal-dual approximation algorithms for a packing-covering pair of problems
We consider a special packing-covering pair of problems. The packing problem is a natural generalization of finding a (weighted) maximum independent set in an interval graph, the covering problem generalizes the problem of finding a (weighted) minimum clique cover in an interval graph. The problem pair involves weights and capacities; we consider the case of unit weights and the case of unit capacities. In each case we describe a simple algorithm that outputs a solution to the packing problem and...
Primal-dual approximation algorithms for a packing-covering pair of problems
We consider a special packing-covering pair of problems. The packing problem is a natural generalization of finding a (weighted) maximum independent set in an interval graph, the covering problem generalizes the problem of finding a (weighted) minimum clique cover in an interval graph. The problem pair involves weights and capacities; we consider the case of unit weights and the case of unit capacities. In each case we describe a simple algorithm that outputs a solution to the packing problem and...
Primitive words and spectral spaces.
Problemas da teoria dos grafos e a sua relação com os problemas da cobertura e da partição de um conjunto
Profile classes and partial well-order for permutations.
Profiles of permutations.