cubic planar graph造句

• In a Hamiltonian cubic planar graph, such an edge coloring is easy to find : use two colors alternately on the cycle, and a third color for all remaining edges.
• Alternatively, a 4-coloring of the faces of a Hamiltonian cubic planar graph may be constructed directly, using two colors for the faces inside the cycle and two more colors for the faces outside.
• The conjecture was significant, because if true, it would have implied the four color theorem : as Tait described, the four-color problem is equivalent to the problem of finding bridgeless cubic planar graphs.
• It is known through computer searches of Gordon Royle and Klas Markstr鰉 that any counterexample must have at least 17 vertices, and any planar; however, the ErdQ
  s Gy醨f醩 conjecture is now known to be true for the special case of 3-connected cubic planar graphs