We prove the following best possible result. Let k 2 be an integer and G be a graph of order n with minimum degree at least k. Assume n 8k - 16 for even n and n 6k-13 for odd n...
We show that in any graph G on n vertices with d(x) + d(y) n for any two nonadjacent vertices x and y, we can fix the order of k vertices on a given cycle and find a hamiltonian c...
We find the graphs of valency at most 7 with the property that any two nonadjacent vertices have either 0 or 2 common neighbours. In particular, we find all semibiplanes of block ...
Ore presented a degree condition involving every pair of nonadjacent vertices for a graph to be hamiltonian. Fan (J. Combin. Theory Ser. B 37 (1984) 221