Author/Authors :
Shao ، Zehui School of Information Science and Engineering - Chengdu University , Deng ، Fei College of Information Science and Technology - Chengdu University of Technology , Li ، Zepeng Key Laboratory of High Confidence Software Technologies - Peking University , Vesel ، Aleksander Faculty of Natural Sciences and Mathematics - University of Maribor
Abstract :
A graceful labeling of a graph G = (V, E) with m edges is an injection f : V (G) → {0, 1, . . . , m} such that the resulting edge labels obtained by |f(u) − f(v)| on every edge uv are pairwise distinct. For natural numbers n and k, where n 2k, a generalized Petersen graph P(n, k) is the graph whose vertex set is {u1, u2, . . . , un} ∪ {v1, v2, . . . , vn} and its edge set is {uiui+1, uivi, vivi+k : 1 ≤ i ≤ n}, where subscript arithmetic is done modulo n. We propose a backtracking algorithm with a specific static variable ordering and dynamic value ordering to find graceful labelings for generalized Petersen graphs. Experimental results show that the presented approach strongly outperforms the standard backtracking algorithm. The proposed algorithm is able to find graceful labelings for all generalized Petersen graphs P(n, k) with n ≤ 75 within only several seconds.
