Graph 作成開始
start creating Graph class
set compiler warning level
fix typo
add display matrics function
finish Graph class
start creating class ShortestPath
Merge remote-tracking branch 'origin/master'

Conflicts:
	c-class/2/Makefile
	c-class/2/graph.cpp
working
add Graph::GetEdgeValue
working shortest_path
Merge remote-tracking branch 'origin/master'

Conflicts:
	c-class/2/shortest_path.cpp
working
debugging
start creating mutex