Let G be a simple graph with no isolated edge. An/-total coloring of a graphG is a mapping Ф : V(G) U E(G) → (1, 2,…… , k) such that no adjacent vertices receive thesame color and no adjacent edges receive ...Let G be a simple graph with no isolated edge. An/-total coloring of a graphG is a mapping Ф : V(G) U E(G) → (1, 2,…… , k) such that no adjacent vertices receive thesame color and no adjacent edges receive the same color. An/-total coloring of a graph G issaid to be adjacent vertex distinguishing if for any pair of adjacent vertices u and v of G, wehave CФ(u) ≠ CФ(v), where CФ(u) denotes the set of colors of u and its incident edges. Theminimum number of colors required for an adjacent vertex distinguishing I-total coloring of GG is called the adjacent vertex distinguishing I-total chromatic number, denoted by Xat(G).In this paper, we characterize the adjacent vertex distinguishing I-total chromatic numberof outerplanar graphs.展开更多
Let x(G^2) denote the chromatic number of the square of a maximal outerplanar graph G and Q denote a maximal outerplanar graph obtained by adding three chords y1 y3, y3y5, y5y1 to a 6-cycle y1y2…y6y1. In this paper...Let x(G^2) denote the chromatic number of the square of a maximal outerplanar graph G and Q denote a maximal outerplanar graph obtained by adding three chords y1 y3, y3y5, y5y1 to a 6-cycle y1y2…y6y1. In this paper, it is proved that △ + 1 ≤ x(G^2) ≤△ + 2, and x(G^2) = A + 2 if and only if G is Q, where A represents the maximum degree of G.展开更多
基金Supported by the National Natural Science Foundation of China(61163037,61163054,61363060)
文摘Let G be a simple graph with no isolated edge. An/-total coloring of a graphG is a mapping Ф : V(G) U E(G) → (1, 2,…… , k) such that no adjacent vertices receive thesame color and no adjacent edges receive the same color. An/-total coloring of a graph G issaid to be adjacent vertex distinguishing if for any pair of adjacent vertices u and v of G, wehave CФ(u) ≠ CФ(v), where CФ(u) denotes the set of colors of u and its incident edges. Theminimum number of colors required for an adjacent vertex distinguishing I-total coloring of GG is called the adjacent vertex distinguishing I-total chromatic number, denoted by Xat(G).In this paper, we characterize the adjacent vertex distinguishing I-total chromatic numberof outerplanar graphs.
文摘Let x(G^2) denote the chromatic number of the square of a maximal outerplanar graph G and Q denote a maximal outerplanar graph obtained by adding three chords y1 y3, y3y5, y5y1 to a 6-cycle y1y2…y6y1. In this paper, it is proved that △ + 1 ≤ x(G^2) ≤△ + 2, and x(G^2) = A + 2 if and only if G is Q, where A represents the maximum degree of G.