The use of Euler's formula in (3,1)*-list coloring
A graph G is called (k,d)*-choosable if, for every list assignment L satisfying |L(v)| = k for all v ∈ V(G), there is an L-coloring of G such that each vertex of G has at most d neighbors colored with the same color as itself. Ko-Wei Lih et al. used the way of discharging to prove that every planar graph without 4-cycles and i-cycles for some i ∈ 5,6,7 is (3,1)*-choosable. In this paper, we show that if G is 2-connected, we may just use Euler’s formula and the graph’s structural properties to prove...