十年OI一场空，_______________
另外 Cs,t(v)=∑Cs,v×Cv,t(s≠v,t≠v,diss,t=diss,v+disv,t) C_{s, t}(v) = \sum C_{s, v} \times C_{v, t} (s \ne v, t \ne v,dis_{s, t} = dis_{s, v} + dis_{v, t})Cs,t(v)=∑Cs,v×Cv,t(s=v,t=v,diss,t=diss,v+disv,t)
