All Apple mobile computers are capable of being charged from 110 volt to 240 volt supplies with the provided leads as standard. The built in power supply module automatically steps to suit the input.
You simply require a suitable plug adapter to match local sockets.
In Europe most sockets accommodate a two prong round pin plug and US to EU adapters can be bought at the airports and many electrical shops for a few dollars
The UK, Ireland and Cyprus however us a differing system with three prong and fused plugs again adapters are readily available.
Apple also sell a kit with a range of adapters for $39.00 Here.