求解双重积分
............\a.cpp
............\a.dsp
............\a.dsw
............\a.ncb
............\a.opt
............\a.plg
............\a.sdf
............\a.sln
............\a.suo
............\a.vcxproj
............\a.vcxproj.filters
............\a.vcxproj.user
............\bjpg.h
............\bjpq.c
............\Debug
............\.....\a.exe
............\.....\a.exe.embed.manifest
............\.....\a.exe.embed.manifest.res
............\.....\a.exe.intermediate.manifest
............\.....\a.ilk
............\.....\a.lastbuildstate
............\.....\a.log
............\.....\a.obj
............\.....\a.pdb
............\.....\a_manifest.rc
............\.....\bjpq.obj
............\.....\CL.read.1.tlog
............\.....\CL.write.1.tlog
............\.....\link-cvtres.read.1.tlog
............\.....\link-cvtres.write.1.tlog
............\.....\link.3660-cvtres.read.1.tlog
............\.....\link.3660-cvtres.write.1.tlog
............\.....\link.3660.read.1.tlog
............\.....\link.3660.write.1.tlog
............\.....\link.8996-cvtres.read.1.tlog
............\.....\link.8996-cvtres.write.1.tlog
............\.....\link.8996.read.1.tlog
............\.....\link.8996.write.1.tlog
............\.....\link.read.1.tlog
............\.....\link.write.1.tlog
............\.....\main.obj
............\.....\mt.read.1.tlog
............\.....\mt.write.1.tlog
............\.....\rc.read.1.tlog
............\.....\rc.write.1.tlog
............\.....\vc100.idb
............\.....\vc100.pdb
............\.....\vc60.idb
............\.....\vc60.pdb
............\ipch
............\....\a-defd485c
............\....\..........\a-f2e45817.ipch
............\main.c