In a proportional contact representation of a planar graph, each vertex is represented by a simple polygon with area proportional to a given weight, and edges are represented by adjacencies between the corresponding pairs of polygons. In this paper we study proportional contact representations that use rectilinear polygons without wasted areas (white space). In this setting, the best known algo...

We study the classic graph drawing problem of drawing a planar graph using straight-line edges with a prescribed convex polygon as the outer face. Unlike previous algorithms for this problem, which may produce drawings with exponential area, our method produces drawings with polynomial area. In addition, we allow for collinear points on the boundary, provided such vertices do not create overlap...

A graph is planar if it can be drawn in the plane without edges crossing. More formally, a graph is planar if it has an embedding in the plane, in which each vertex is mapped to a distinct point P (v), and edge (u; v) to simple curves connecting P (u); P (v), such that curves intersect only at their endpoints. Examples of planar graphs: Pn, Trees, Cycles, X-tree, K4. Examples of non-planar grap...

A bar 1-visibility drawing of a graph G is a drawing of G where each vertex is drawn as a horizontal line segment called a bar, each edge is drawn as a vertical line segment where the vertical line segment representing an edge must connect the horizontal line segments representing the end vertices and a vertical line segment corresponding to an edge intersects at most one bar which is not an en...

in this paper we study the coprime graph of a group $g$. the coprime graph of a group $g$, is a graph whose vertices are elements of $g$ and two distinct vertices $x$ and $y$ are adjacent iff $(|x|,|y|)=1$. in this paper we classify all the groups which the coprime graph is a complete r-partite graph or a planar graph. also we study the automorphism group of the coprime graph.

Given an n-vertex outer-planar graph G and a set P of n points in the plane, we present an O(n log 3 n) time and O(n) space algorithm to compute a straight-line embedding of G in P, improving upon the algorithm in GMPP91, CU96] that requires O(n 2) time. Our algorithm is near-optimal as there is an (n log n) lower bound for the problem BMS95]. We present a simpler O(nd) time and O(n) space algo...

In a graph, vertex dominates itself and its neighbors. A subset S of vertices graph G is double dominating set if every at least twice. The domination number γ ×2 ( ) the minimum cardinality . this paper, we prove that maximal outerplanar order n bounded above by + k /2, where pairs consecutive degree two with distance 3 on outer cycle. We also ×2( ≤ 5 /8 for Hamiltonian planar ≥ 7.

a fullerene graph is a 3−connected planar graph whose faces are pentagons and hexagons.the clar number of a fullerene is the maximum size of sextet patterns, the sets of disjointhexagons which are all m-alternating for a kekulé structure m of f. an exact formula of clarnumber of some fullerene graphs and a class of carbon nanocones are obtained in this paper.

An outerplanar graph is a planar graph which can be embedded in the plane in such a way that all of vertices lie on the outer boundary. Many chemical compounds are known to be expressed by outerplanar graphs. An externally extensible outerplanar graph pattern (eeo-graph pattern for short) represents a graph pattern common to a finite set of outerplanar graphs like a dataset of chemical compound...