计算机图形学的问题,运行时编译成功,但是运行不出,老出以下错误

Linking...
gra.obj : error LNK2005: _main already defined in gra1.obj
LIBCD.lib(wincrt0.obj) : error LNK2001: unresolved external symbol _WinMain@16
Debug/graphic1.exe : fatal error LNK1120: 1 unresolved externals
执行 link.exe 时出错.

graphic1.exe - 1 error(s), 0 warning(s)

工程类型错了console