“一定”何时会发生 Lemma 24.14(Convergence property) Let G=(V,E)be a weighted,directed graph with weight function w:ER let sV be a source vertex,and let sbe a shortest path in G for some vertices u,vV.Suppose that G is initialized by INITIALIZE-SINGLE- SOURCE(G,s)and then a sequence of relaxation steps that includes the call RELAX(u,v,w)is executed on the edges of G.If u.d =(s,u)at any time prior to the call,then v.d=8(s,v)at all times after the call.“一定”何时会发生