代码
class Queue:
def __init__(self,size):
self.items = []
self.size = size
def is_empty(self):
return self.items == []
def length(self):
return len(self.items)
def push(self, item):
if self.length() == self.size:
raise ValueError("队列已满")
else:
self.items.append(item)
def pop(self):
if self.is_empty():
raise ValueError("队列为空")
return self.items.pop(0)
def peek(self):
if self.is_empty():
raise ValueError("队列为空")
return self.items[0]
if __name__ == "__main__":
queue = Queue(3)
queue.push(1)
queue.push(2)
queue.push(3)
print(queue.pop())
queue.push(4)
print(queue.length())
print(queue.peek())
print(queue.pop())
print(queue.pop())
print(queue.pop())
结果
