45 lines
1.1 KiB
Python
45 lines
1.1 KiB
Python
"""
|
|
Queue based upon array
|
|
用数组实现的队列
|
|
|
|
Author: Wenru
|
|
"""
|
|
|
|
from typing import Optional
|
|
|
|
class ArrayQueue:
|
|
|
|
def __init__(self, capacity: int):
|
|
self._items = []
|
|
self._capacity = capacity
|
|
self._head = 0
|
|
self._tail = 0
|
|
|
|
def enqueue(self, item: str) -> bool:
|
|
if self._tail == self._capacity:
|
|
if self._head == 0:
|
|
return False
|
|
else:
|
|
for i in range(0, self._tail - self._head):
|
|
<<<<<<< HEAD
|
|
self._data[i] = self._items[i + self._head]
|
|
=======
|
|
self._items[i] = self._items[i + self._head]
|
|
>>>>>>> upstream/master
|
|
self._tail = self._tail - self._head
|
|
self._head = 0
|
|
|
|
self._items.insert(self._tail, item)
|
|
self._tail += 1
|
|
return True
|
|
|
|
def dequeue(self) -> Optional[str]:
|
|
if self._head != self._tail:
|
|
item = self._items[self._head]
|
|
self._head += 1
|
|
return item
|
|
|
|
def __repr__(self) -> str:
|
|
return " ".join(item for item in self._items[self._head : self._tail])
|
|
|