WALCOM: Algorithms and Computation 13th International Conference, WALCOM 2019, Guwahati, India, February 27 - March 2, 2019, Proceedings - Das, Gautam K.; Das, Gautam K.; Mandal, Partha S.; Mandal, Partha S.; Mukhopadhyaya, Krishnendu; Mukhopadhyaya, Krishnendu; Nakano, Shin-ichi; Nakano, Shin-ichi (Springer International Publishing : Imprint: Springer, 2019)