I believe they all use the european style - 2 round plugs. The hotel we were at in Basel used that kind. If you've gotten your green Tauck travel book it should have some information in it. You can also check the Before You Go and Accommodations page on the website here for your specific tour.
Yes, every country in Europe (except the UK) uses the same round two pin plug for ungrounded appliances. If you need a grounded plug, they are more country specific. Do a search on the web or Amazon for "Switzerland grounded adapter."
If you're doing any amount of traveling I'd suggest getting a couple of these: https://www.amazon.com/Insten-Universal-Travel-Charger-Adapter/dp/B000YN01X4
They will change pretty much any plug into any plug. I've used mine all over the world, haven't found a socket that they won't fit yet.
(Edit: Just noticed it's too late for your trip but maybe others have the same question ;p)
Comments
https://www.amazon.com/Insten-Universal-Travel-Charger-Adapter/dp/B000YN01X4
They will change pretty much any plug into any plug. I've used mine all over the world, haven't found a socket that they won't fit yet.
(Edit: Just noticed it's too late for your trip but maybe others have the same question ;p)