2 列主元消去法
..............\1.cpp
..............\1.dsp
..............\1.dsw
..............\1.ncb
..............\1.opt
..............\1.plg
..............\Debug
..............\.....\1.exe
..............\.....\1.ilk
..............\.....\1.obj
..............\.....\1.pch
..............\.....\1.pdb
..............\.....\vc60.idb
..............\.....\vc60.pdb
..............\in2.txt
..............\out2.txt