My site has a online code for interview questions practicing purpose. So far
it only supports C++, but I plan to add support for other languages (like
Java) soon.
Just click on "show i has 1337 code coding panel" to open up the coding
panel. You can write code on the right box, and the code output will
immediately be shown after you clicked "Run code".
It also has "Interview questions online judge" for testing your solution.
There are other sites such as ideone.com and codepad.org, but I think my
coding panel has the fastest feedback after changing code. Please use it and
leave a comment to me, and I'll try to improve it as best I can.
Thanks!