mirror of
https://github.com/TheAlgorithms/Python.git
synced 2024-11-24 05:21:09 +00:00
384c407a26
* enhance the implementation of queue using list * enhance readability of queue_on_list.py * rename 'queue_on_list' to 'queue_by_list' to match the class name
142 lines
3.0 KiB
Python
142 lines
3.0 KiB
Python
"""Queue represented by a Python list"""
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from collections.abc import Iterable
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from typing import Generic, TypeVar
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_T = TypeVar("_T")
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class QueueByList(Generic[_T]):
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def __init__(self, iterable: Iterable[_T] | None = None) -> None:
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"""
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>>> QueueByList()
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Queue(())
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>>> QueueByList([10, 20, 30])
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Queue((10, 20, 30))
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>>> QueueByList((i**2 for i in range(1, 4)))
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Queue((1, 4, 9))
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"""
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self.entries: list[_T] = list(iterable or [])
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def __len__(self) -> int:
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"""
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>>> len(QueueByList())
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0
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>>> from string import ascii_lowercase
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>>> len(QueueByList(ascii_lowercase))
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26
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>>> queue = QueueByList()
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>>> for i in range(1, 11):
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... queue.put(i)
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>>> len(queue)
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10
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>>> for i in range(2):
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... queue.get()
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1
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2
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>>> len(queue)
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8
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"""
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return len(self.entries)
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def __repr__(self) -> str:
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"""
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>>> queue = QueueByList()
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>>> queue
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Queue(())
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>>> str(queue)
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'Queue(())'
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>>> queue.put(10)
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>>> queue
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Queue((10,))
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>>> queue.put(20)
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>>> queue.put(30)
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>>> queue
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Queue((10, 20, 30))
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"""
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return f"Queue({tuple(self.entries)})"
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def put(self, item: _T) -> None:
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"""Put `item` to the Queue
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>>> queue = QueueByList()
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>>> queue.put(10)
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>>> queue.put(20)
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>>> len(queue)
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2
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>>> queue
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Queue((10, 20))
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"""
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self.entries.append(item)
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def get(self) -> _T:
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"""
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Get `item` from the Queue
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>>> queue = QueueByList((10, 20, 30))
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>>> queue.get()
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10
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>>> queue.put(40)
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>>> queue.get()
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20
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>>> queue.get()
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30
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>>> len(queue)
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1
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>>> queue.get()
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40
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>>> queue.get()
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Traceback (most recent call last):
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...
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IndexError: Queue is empty
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"""
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if not self.entries:
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raise IndexError("Queue is empty")
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return self.entries.pop(0)
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def rotate(self, rotation: int) -> None:
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"""Rotate the items of the Queue `rotation` times
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>>> queue = QueueByList([10, 20, 30, 40])
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>>> queue
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Queue((10, 20, 30, 40))
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>>> queue.rotate(1)
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>>> queue
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Queue((20, 30, 40, 10))
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>>> queue.rotate(2)
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>>> queue
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Queue((40, 10, 20, 30))
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"""
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put = self.entries.append
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get = self.entries.pop
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for _ in range(rotation):
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put(get(0))
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def get_front(self) -> _T:
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"""Get the front item from the Queue
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>>> queue = QueueByList((10, 20, 30))
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>>> queue.get_front()
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10
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>>> queue
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Queue((10, 20, 30))
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>>> queue.get()
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10
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>>> queue.get_front()
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20
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"""
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return self.entries[0]
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if __name__ == "__main__":
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from doctest import testmod
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testmod()
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