PHP bidirectional Queue Implementation code

1, what is a two-way queue Deque, full name double-ended queue, is a data structure that has the nature of queues and stacks. Elements in a double-ended queue can be ejected from both ends, and their qualifying insert and delete operations are performed at both ends of the table. A two-way queue (a double-ended queue) is like a queue, but an element can be added or removed at either end. Reference: http://zh.wikipedia.org/zh-cn/%E5%8F%8C%E7%AB%AF%E9%98%9F%E5%88%97 2,php implementing two-way queuing code Class Doublequeue { Public $queue = Array (); /** (tail) queue **/ Public Function AddLast ($value) { Return Array_push ($this->queue, $value); } /** (tail) out of the team **/ Public Function Removelast () { Return Array_pop ($this->queue); } /** (head) queue **/ Public Function AddFirst ($value) { Return Array_unshift ($this->queue, $value); } /** (head) out of the team **/ Public Function Removefirst () { Return Array_shift ($this->queue); } /** emptying the queue **/ Public Function Makeempty () { unset ($this->queue); } /** Get column Header **/ Public Function GetFirst () { Return Reset ($this->queue); } /** get end of column **/ Public Function GetLast () { Return End ($this->queue); } /** Get length **/ Public Function GetLength () { Return count ($this->queue); } } Copy Code

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