【摘要】 设G为n(≥3)阶2连通图,δ≤δ~*≤Δ,对任意x∈V(G),记D(x)={y|y∈V(G)\{x},d(x,y)≤2},D~*(x)={y|y∈(D(x)∪{x}),d(y)<δ~*},本文证明:如果|D~*(x)|<d(x),则G中有长至少为min{n,2δ~*}的圈。更多还原

【Abstract】 Let G be a 2-connected graph with n(≥3) vertices and δ≤δ≤△ and for any x∈V(G)we suppose D(x) = {y\y∈V(G)\{x},d(x, y)≤2} and D*(x) = {y\y∈(D(x)∪{x}), d(y)<δ*} ,ii is proved that if |D*(x)|<d(x), then there will be a cycle in G with a length of min {n,2δ*} at least.更多还原