We show that a context-free grammar of size produces single string $w$?> length $n$?> (such is also called straight-line program) can be transformed in linear time into for $\mathcal {O}(m)$?> , whose unique derivation tree has depth {O}(\log n)$?> . This solves an open problem the area grammar-based compression, improves many results this area, and greatly simplifies existing const...

We study straight-line drawings of graphs with few segments and few slopes. Optimal results are obtained for all trees. Tight bounds are obtained for outerplanar graphs, 2-trees, and planar 3-trees. We prove that every 3-connected plane graph on n vertices has a plane drawing with at most 5n/2 segments and at most 2n slopes, and that every cubic 3-connected plane graph has a plane drawing with ...