Ubuntu18.04版本安装gcc、g++
sudo apt-get install aptitude sudo aptitude install gcc g++
输入 gcc --version，输出以下信息，说明已经装好了。
gcc --version gcc (Ubuntu 7.5.0-3ubuntu1~18.04) 7.5.0 Copyright (C) 2017 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
