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| 1 | +# Author: OMKAR PATHAK |
| 2 | +# Created On: 3rd August July 2017 |
| 3 | + |
| 4 | +# queue implementation |
| 5 | +class Queue(object): |
| 6 | + ''' |
| 7 | +
|
| 8 | + size : return the current size of the queue |
| 9 | + enqueue : insert an item into the queue |
| 10 | + dequeue : remove an item from the queue which was first inserted |
| 11 | + isEmpty : check if the queue is empty |
| 12 | +
|
| 13 | + ''' |
| 14 | + |
| 15 | + def __init__(self, limit = 10): |
| 16 | + ''' |
| 17 | + @param: limit: queue size |
| 18 | + ''' |
| 19 | + self.queue = [] |
| 20 | + self.front = None |
| 21 | + self.rear = None |
| 22 | + self.limit = limit |
| 23 | + self.size = 0 |
| 24 | + |
| 25 | + # for printing the contents of the queue |
| 26 | + def __str__(self): |
| 27 | + return ' '.join([str(i) for i in self.queue]) |
| 28 | + |
| 29 | + # to check if queue is empty |
| 30 | + def isEmpty(self): |
| 31 | + return self.size <= 0 |
| 32 | + |
| 33 | + # to add an element from the rear end of the queue |
| 34 | + def enqueue(self, data): |
| 35 | + if self.size >= self.limit: |
| 36 | + return -1 # queue overflow |
| 37 | + else: |
| 38 | + self.queue.append(data) |
| 39 | + |
| 40 | + # assign the rear as size of the queue and front as 0 |
| 41 | + if self.front is None: |
| 42 | + self.front = self.rear = 0 |
| 43 | + else: |
| 44 | + self.rear = self.size |
| 45 | + |
| 46 | + self.size += 1 |
| 47 | + |
| 48 | + # to pop an element from the front end of the queue |
| 49 | + def dequeue(self): |
| 50 | + if self.isEmpty(): |
| 51 | + return -1 # queue underflow |
| 52 | + else: |
| 53 | + self.size -= 1 |
| 54 | + if self.size == 0: |
| 55 | + self.front = self.rear = 0 |
| 56 | + else: |
| 57 | + self.rear = self.size - 1 |
| 58 | + return self.queue.pop(0) |
| 59 | + |
| 60 | + # return the size of the queue |
| 61 | + def size(self): |
| 62 | + return self.size |
| 63 | + |
| 64 | + # easily retrieve the source code of the Queue class |
| 65 | + def get_code(self): |
| 66 | + import inspect |
| 67 | + return inspect.getsource(Queue) |
| 68 | + |
| 69 | +class Deque(object): |
| 70 | + ''' |
| 71 | +
|
| 72 | + isEmpty : checks whether the deque is empty |
| 73 | + isFull : checks whether the deque is full |
| 74 | + insertRear : inserts an element at the rear end of the deque |
| 75 | + insertFront : inserts an element at the front end of the deque |
| 76 | + deleteRear : deletes an element from the rear end of the deque |
| 77 | + deleteFront : deletes an element from the front end of the deque |
| 78 | +
|
| 79 | + ''' |
| 80 | + |
| 81 | + def __init__(self, limit = 10): |
| 82 | + self.queue = [] |
| 83 | + self.limit = limit |
| 84 | + |
| 85 | + def __str__(self): |
| 86 | + return ' '.join([str(i) for i in self.queue]) |
| 87 | + |
| 88 | + # check if queue is empty |
| 89 | + def isEmpty(self): |
| 90 | + return len(self.queue) <= 0 |
| 91 | + |
| 92 | + # check if queue is full |
| 93 | + def isFull(self): |
| 94 | + return len(self.queue) >= self.limit |
| 95 | + |
| 96 | + # for inserting at rear |
| 97 | + def insertRear(self, data): |
| 98 | + if self.isFull(): |
| 99 | + return |
| 100 | + else: |
| 101 | + self.queue.insert(0, data) |
| 102 | + |
| 103 | + # for inserting at front end |
| 104 | + def insertFront(self, data): |
| 105 | + if self.isFull(): |
| 106 | + return |
| 107 | + else: |
| 108 | + self.queue.append(data) |
| 109 | + |
| 110 | + # deleting from rear end |
| 111 | + def deleteRear(self): |
| 112 | + if self.isEmpty(): |
| 113 | + return |
| 114 | + else: |
| 115 | + return self.queue.pop(0) |
| 116 | + |
| 117 | + # deleting from front end |
| 118 | + def deleteFront(self): |
| 119 | + if self.isFull(): |
| 120 | + return |
| 121 | + else: |
| 122 | + return self.queue.pop() |
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