多段图\前向\data.txt
......\....\fgraph.cpp
......\....\fgraph.dsp
......\....\fgraph.dsw
......\....\fgraph.ncb
......\....\fgraph.opt
......\....\fgraph.plg
......\后向\bgraph.cpp
......\....\bgraph.dsp
......\....\bgraph.dsw
......\....\bgraph.ncb
......\....\bgraph.opt
......\....\bgraph.plg
......\....\data.txt
......\前向
......\后向
多段图