C++ Deque
In the previous page, your learned that elements in a queue are added at the end and removed from the front.
A deque (stands for double-ended queue) however, is more flexible, as elements can be added and removed from both ends (at the front and the back). You can also access elements by index numbers.
To use a deque, you have to include the <deque> header file:
// Include the deque library #include <deque>