打算从头读一遍the c programming language，记一些笔记
1 .1 about printf we can refer the linux source code about printf system call implement,
1.2 the varibles and Arithmetic expression
the arithmetic operator will have integer or float function..if one is not integer, the operator will be interger......
from 1-9 exercise...logic progress is very important.....you must know what where your program is going.......