Homework 8 (due Thursday, October 21st)

1.  4F in Van Lint.  (See the hint.)

2.  4H in Van Lint.  (See the hint.)

3.  6A in Van Lint. (See the hint.)

4.  Let G be a connected graph with n ≥ 3 vertices such that d(x)+d(y) ≥ n for every pair of non-adjacent vertices x, y of G, where d(x) and d(y) are the degree of x and y respectively.  Show that G has an Hamiltonian cycle.