0001 template <typename Tv, typename Te> struct DijkPU { //针对Dijkstra算法的顶点优先级更新器
0002    virtual void operator()(Graph<Tv, Te>* g, Rank v, Rank u) {
0003       if (UNDISCOVERED == g->status(u) //对于v每一尚未被发现的邻接顶点u，按Dijkstra策略
0004          && g->prio(u) > g->prio(v) + g->wt(v, u)) { //策略择优
0005             g->prio(u) = g->prio(v) + g->wt(v, u); //更新优先级（数）
0006             g->parent(u) = v; //更新父亲
0007       } //if
0008    } //operator
0009 }; //DijkPU