Need following functions in queue:

File location - Queue

1. empty() – Returns whether the queue is empty.
2. size() – Returns the size of the queue.
3. front() – Function returns a the first element of the queue.
4. back() – Function returns a the last element of the queue.
5. push(g) – Function adds the element ‘g’ at the end of the queue.
6. pop() – Function deletes the first element of the queue.

Example:

Queue q = [1,2,3,4,5,6];
q.empty() false
q.size() 6
q.front() 1
q.back() 6
q.push(10) [1, 2, 3, 4, 5, 6, 10]
q.pop() [2, 3, 4, 5, 6, 10]