function?[d?pred]?=?dijkstra_sp（Auvarargin）
%?DIJKSTRA_SP?Compute?the?weighted?single?source?shortest?path?problem.
%
%?Dijkstra‘s?algorithm?for?the?single?source?shortest?path?problem?only
%?works?on?graphs?without?negative?edge?weights.
%
%?This?method?works?on?weighted?directed?graphs?without?negative?edge
%?weights.
%?The?runtime?is?O（V?log?（V））.
%
%?See?the?shortest_paths?function?for?calling?information.??This?function?
%?just?calls?shortest_paths（...struct（‘algname‘‘dijkstra‘））;
%
%?The?options?structure?can?contain?a?visitor?for?the?Dijkstra?algorithm.??
%
%?See?http://www.boost.org/libs/graph/doc/DijkstraVisitor.html?for?a?
%?description?of?the?events.
%?
%?visitor?is?a?struct?with?the?following?optional?fields
%????vis.initialize_vertex（u）
%????vis.discover_vertex（u）
%????vis.