2020/2/3 数据结构：顺序队列

顺序队列

class QueueError(Exception):
    pass
class SQueue:
    def __init__(self):
        self._elems=[]
    def is_empty(self):
        return self._elems==[]
    def enqueue(self,elem):
        self._elems.append(elem)
    def dequeue(self):
        if not self._elems:
            raise QueueError("queue is empty")
        return self._elems.pop(0)
if __name__=="__main__":
    sq=SQueue()
    print(sq.is_empty())
    sq.enqueue(10)
    sq.enqueue(20)
    sq.enqueue(30)
    while not sq.is_empty():
        print(sq.dequeue())