Far Cry 3 disc share help

No. Edit how do you mean? If you buy it from the steam store you won't get a disc right... and I don't know if you have to get a Uplay acc for it

plz help :(

It requires to login into uplay for game activation.

You could activate it on one pc and switch it to another through Ubisoft's customer service should you have to, but you can't just get a free game any time you want to. Life just doesn't work like that.

You can activate it on a Uplay account and then use that account from 2 different PCs I think.

Truthfully? No. No you can't. When you're buying a game on PC, you're buying it for one person/one computer/one account. If you can get that account on multiple computers and play it that way, power to you, but don't expect it to work out.

Far Cry 3 requires UPlay to play it, even on Steam.
You can install it on as many PCs you want using the same disc (you won't need the disc to play it) AND the same UPlay account.
However, you have to log in into your UPlay account to be able to play the game and you can only be logged in on one PC at a time.
Usually when you connect to a PC you will be disconnected from the other PC.
Also, you do not need the disc to install the game since the game can be downloaded using UPlay (unlike on Steam, UPlay downloads the kit - same content you have on the disc - and you have to manally install the game after that). Updates should be done automatically.
Hope this helps.