Validate if a given string is numeric.
Some examples:
"0"=>true
" 0.1 "=>"abc"=>false
"1 a"=>"2e10"=>true
Note:It is intended for the problem statement to be ambiguous. You should gather all requirements up front before implementing one.
Update (2015-02-10):
The signature of theC++function had been updated. If you still see your function signature accepts aconst char *argument,please click the reload buttonto reset your code deFinition.
1）可以直接的用很多if判断。
2）网上有用有限状态机的。http://www.jb51.cc/article/p-hosklxsd-ve.htmlhttp://www.jb51.cc/article/p-xyiwheub-rn.html
3）正则表达式。
不太懂，mark一下。
