-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathQueues.py
334 lines (245 loc) · 8.62 KB
/
Queues.py
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
"""
Author: Ahmad Elkholi
Created on Wed Mar 02 23:54:12 2022
Queue data structure implementations using lists and linked lists, and Circular Queue implementation.
"""
from typing import Any
from LinkedLists import SinglyLL
FULL_QUEUE_ERROR_MSG = "Maximum queue capacity reached, unable to store more elements."
EMPTY_QUEUE_ERROR_MSG = "Queue is empty."
class Queue:
"""List-based implementation of Queue data structure.
Parameters
----------
capacity: int
Determine the maximum amount of elements a Queue can carry. If unspecified, Queue capacity will be limitless.
default = None
vals: iterable
a group of elements that are added to the Queue during its construction. If unspecified, an empty Queue is created. If the number of elements in vals exceeds the specified capacity, An assertion error is raised.
default = None
Methods
-------
empty() -> bool:
Check if the queue is empty.
full() -> bool:
Check if the queue is full.
enqueue(element) -> self:
Add an element to the end of the queue.
dequeue() -> Any:
pop the first element in the queue.
peek() -> Any:
Access the first element of the queue.
delete() -> None:
Remove all elements from the Queue.
"""
def __init__(self, capacity: int = None, vals: list = None) -> None:
self._assert_params(capacity, vals)
self._capacity = capacity
self._elements = list(vals) if vals else []
self._size = len(self._elements)
def __repr__(self) -> str:
return f"Queue({self._elements})"
def __len__(self) -> int:
return self._size
def __iter__(self):
self._queue_iterator = iter(self._elements)
return self
def __next__(self) -> Any:
return next(self._queue_iterator)
def __contains__(self, element) -> bool:
return element in self._elements
def _assert_params(self, capacity, vals) -> None:
if capacity is not None:
if not isinstance(capacity, int):
raise TypeError("capacity must be of type 'int'.")
if capacity <= 0:
raise ValueError("capacity must be greater than zero.")
if vals is not None:
if not hasattr(vals, "__iter__"):
raise TypeError("vals is not iterable")
if capacity is not None:
assert (
len(vals) <= capacity
), f"Cannot create queue with {len(vals)} elements and max capacity of {capacity}."
def empty(self) -> bool:
"""Check if the queue is empty."""
return self._size == 0
def full(self) -> bool:
"""Check if the queue is full."""
return self._size == self._capacity
def enqueue(self, element: Any):
"""Add an element to the end of the queue.
Parameters
----------
element: Any
The element that is added to the queue.
Returns
-------
self
"""
assert not self.full(), FULL_QUEUE_ERROR_MSG
self._elements.append(element)
self._size += 1
return self
def dequeue(self) -> Any:
"""pop the first element in the queue.
Returns
-------
Element: Any
The first element in the queue.
"""
assert not self.empty(), EMPTY_QUEUE_ERROR_MSG
self._size -= 1
return self._elements.pop(0)
def peek(self) -> Any:
"""Access the first element of the queue.
Returns
-------
Element: Any
The first element in the queue.
"""
assert not self.empty(), EMPTY_QUEUE_ERROR_MSG
return self._elements[0]
def delete(self) -> None:
"""Remove all elements from the Queue."""
self._elements = []
self._size = 0
class QueueLL(Queue):
"""LinkedList-based implementation of Queue data structure.
Parameters
----------
capacity: int
Determine the maximum amount of elements a Queue can carry. If unspecified, Queue capacity will be limitless.
default = None
vals: iterable
a group of elements that are added to the Queue during its construction. If unspecified, an empty Queue is created. If the number of elements in vals exceeds the specified capacity, An assertion error is raised.
default = None
Methods
-------
empty() -> bool:
Check if the queue is empty.
full() -> bool:
Check if the queue is full.
enqueue(element) -> self:
Add an element to the end of the queue.
dequeue() -> Any:
pop the first element in the queue.
peek() -> Any:
Access the first element of the queue.
delete() -> None:
Remove all elements from the Queue.
"""
def __init__(self, capacity: int = None, vals: list = None) -> None:
self._assert_params(capacity, vals)
self._capacity = capacity
self._elements = SinglyLL(vals)
self._size = len(self._elements)
def enqueue(self, element: Any):
"""Add an element to the end of the queue.
Parameters
----------
element: Any
The element that is added to the queue.
Returns
-------
self
"""
assert not self.full(), FULL_QUEUE_ERROR_MSG
self._elements.insert(element)
self._size += 1
return self
def dequeue(self) -> Any:
"""pop the first element in the queue.
Returns
-------
Element: Any
The first element in the queue.
"""
assert not self.empty(), EMPTY_QUEUE_ERROR_MSG
removed_element = self.peek()
self._elements.pop(0)
self._size -= 1
return removed_element
def delete(self) -> None:
"""Remove all elements from the Queue."""
self._elements.delete()
self._size = 0
class QueueCirc(Queue):
"""a List-based implementation of the Circular Queue data structure. It is a special version of queue where the last element of the queue is connected to the first element of the queue forming a circle.
The operations are performed based on FIFO (First In First Out) principle. It is also called 'Ring Buffer'.
Parameters
----------
capacity: int
Determine the maximum amount of elements a Queue can carry.
Methods
-------
empty() -> bool:
Check if the queue is empty.
full() -> bool:
Check if the queue is full.
enqueue(element) -> self:
Add an element to the end of the queue.
dequeue() -> Any:
pop the first element in the queue.
peek() -> Any:
Access the first element of the queue.
delete() -> None:
Remove all elements from the Queue.
"""
def __init__(self, capacity: int) -> None:
self._capacity = capacity
self._elements = capacity * [None]
self._first = 0
self._last = -1
self._size = 0
def __len__(self) -> int:
return self._size
def empty(self) -> bool:
"""Check if the queue is empty."""
return self._size == 0
def full(self) -> bool:
"""Check if the queue is full."""
return self._size == self._capacity
def enqueue(self, element: Any):
"""Add an element to the end of the queue.
Parameters
----------
element: Any
The element that is added to the queue.
Returns
-------
self
"""
assert not self.full(), FULL_QUEUE_ERROR_MSG
self._last = (self._last + 1) % self._capacity
self._elements[self._last] = element
self._size += 1
return self
def dequeue(self) -> Any:
"""pop the first element in the queue.
Returns
-------
Element: Any
The first element in the queue.
"""
assert not self.empty(), EMPTY_QUEUE_ERROR_MSG
removed_element = self._elements[self._first]
self._elements[self._first] = None
self._first = (self._first + 1) % self._capacity
self._size -= 1
return removed_element
def peek(self) -> Any:
"""Access the first element in the queue.
Returns
-------
Element: Any
The first element in the queue.
"""
assert not self.empty(), EMPTY_QUEUE_ERROR_MSG
return self._elements[self._first]
def delete(self) -> None:
"""Remove all elements from the Queue."""
self._elements = self._capacity * [None]
self._first = 0
self._last = -1
self._size = 0