摘要
A k-total coloring of a graph G is a mapping φ: V(G) U E(G) → {1, 2,..., k} such that no two adjacent or incident elements in V(G) U E(G) receive the same color. Let f(v) denote the sum of the color on the vertex v and the colors on all edges incident with v. We say that ~ is a k-neighbor sum distinguishing total coloring of G if f(u) ≠ f(v) for each edge uv C E(G). Denote X" (G) the smallest value k in such a coloring of G. Pilgniak and Wo/niak conjectured that for any simple graph with maximum degree △(G), X"(G) ≤ 3. In this paper, by using the famous Combinatorial Nullstellensatz, we prove that for Ka-minor free graph G with △(G) ≥ 5, X"(G) = △(G) + 1 if G contains no two adjacent A-vertices, otherwise, X"(G) = △(G) + 2.
A k-total coloring of a graph G is a mapping φ: V(G) U E(G) → {1, 2,..., k} such that no two adjacent or incident elements in V(G) U E(G) receive the same color. Let f(v) denote the sum of the color on the vertex v and the colors on all edges incident with v. We say that ~ is a k-neighbor sum distinguishing total coloring of G if f(u) ≠ f(v) for each edge uv C E(G). Denote X" (G) the smallest value k in such a coloring of G. Pilgniak and Wo/niak conjectured that for any simple graph with maximum degree △(G), X"(G) ≤ 3. In this paper, by using the famous Combinatorial Nullstellensatz, we prove that for Ka-minor free graph G with △(G) ≥ 5, X"(G) = △(G) + 1 if G contains no two adjacent A-vertices, otherwise, X"(G) = △(G) + 2.