Travel / Youth Cities to enjoy in Poland [6]

Hello everyone; i will be travelling across Europe next week, and i will stay 10-15 days in Poland.

I am looking for energic cities; that are full of young people like me (college students would be best), have many bars, pubs, cafes, etc. and a nightlife of course.

I will be going to Warszawa, Krakow, Lodz, Wroklaw and Poznan. Are those cities enough for Poland? I am looking for new destinations other than those. The city can be big or small in terms of population. the only thing i am looking is either the density of young population is high, or number of young people is high (I am assuming if there is young people population in a city, then it is also energic, live, and have lots of bars, pubs, cafes)

To be honest i enjoy small cities much (as long as there are young population out there) because i dont like too crowded places. So please advise me.

Thanks and

Cheers from Brasil!