Update 19 files

- /Pth/algorithms/.gitkeep
- /Pth/algorithms/alt.cpp
- /Pth/algorithms/alt.h
- /Pth/algorithms/astar.cpp
- /Pth/algorithms/astar.h
- /Pth/algorithms/dijkstra.cpp
- /Pth/algorithms/dijkstra.h
- /Pth/utils/.gitkeep
- /Pth/utils/graphgenerator.cpp
- /Pth/utils/graphgenerator.h
- /Pth/utils/performancetest.cpp
- /Pth/utils/performancetest.h
- /Pth/.gitignore
- /Pth/.gitkeep
- /Pth/graphgenerator.h
- /Pth/main.cpp
- /Pth/pth.pro
- /Pth/pth.pro.user
- /Pth/pth_en_US.ts