["C语言练习"]
C语言的资料：
[http://retards.org/library/technology/computers/programming/c/k_and_r_book/docs/K_R/kandr.html The C Programming Language 2nd Edition]
[http://users.powernet.co.uk/eton/kandr2/ Answer to TCPL]
[http://www.faqs.org/faqs/C-faq/faq/ Ansi C FAQ]