linkedqueue.output

这是数据结构、算法与应用-C++语言描述的代码

Queue back is 1
Queue back is 2
Queue back is 3
Queue back is 4
Queue should be 1234, front to back
The queue is not empty
The queue size is 4
Queue front is 1
Popped front element
Queue front is 2
Popped front element
Queue front is 3
Popped front element
Queue front is 4
Popped front element
Last pop failed 
Invalid operation on empty queue