SOFSEM 2015: theory and practice of computer science 41st international conference on current trends in theory and practice of computer science Pec pod Sněžkou, Czech Republic, January 24-29, 2015. Proceedings - Italiano, Giuseppe F.; Margaria-Steffen, Tiziana; Pokorný, Jaroslav; Quisquater, Jean-Jacques; Wattenhofer, Roger (Lecture Notes in Computer Science, 2015)