alane143:
Hello,
Deque is a c++ library, you can't use it in Arduino. Your code also uses some other c++ features (such as the auto keyword). Make sure you are writing code for arduino, not c++.
Hmmm, If Arduino does not support STL, then what is this link all about?
As far as Auto, auto is par of the c++ 11 standard. I do believe it is supported, will have to test this tonight when I get home.