Recently,

I have seen subscriber 's youtube channel, It is very useful and I thank all the coders who upload their screencasts and helping for the community.

Interesting thing is,
He uses some C++ code to generate random test cases to test his solution and to hack some other's solution
I would like to hear some tips on how to generate random test cases in C++ ?

Yeah , rand() function can be used but shows same integer every time after it's execution.
So, It would be interesting, If some of the coders in this community share their tips on how to generate those test cases.
I even like to see tourist coding during codeforces/topcoder/codechef rounds.

Hope that he notices this post and uploads screencast as Petr, Egor, subscriber does :)