65 lines
1.7 KiB
Python
65 lines
1.7 KiB
Python
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class FIFOqueue:
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def __init__(self, item = 0) -> None:
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"""
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creates the FIFOqueue object given an item,
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will default to 0 if no item is passed.
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firstNum: any
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"""
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self.arr = [item]
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def enqueue(self, n) -> None:
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"""
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adds n to the end of the queue in O(1) time
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n: Any
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"""
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self.arr.append(n)
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def dequeue(self):
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"""
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removes the first element from the queue and returns it in O(1) time
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"""
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return self.arr.pop(0)
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def front(self):
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"""
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returns the first element of the queue in O(1) time
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"""
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return self.arr[0]
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def rear(self):
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"""
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returns the last element of the queue in O(1) time
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"""
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return self.arr[-1]
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# main
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if __name__ == '__main__':
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exampleFIFO = FIFOqueue(1)
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# now our queue should look like [1] after initialization
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print(f"queue after initialization: {exampleFIFO.arr}")
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exampleFIFO.enqueue(5)
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# now our queue should look like [1, 5]
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print(f"queue after enqueueing 5: {exampleFIFO.arr}")
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print(f"If we dequeue, we are removing {exampleFIFO.dequeue()} from the queue")
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# now our queue should look like [5]
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print(f"queue after dequeue: {exampleFIFO.arr}")
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exampleFIFO.enqueue(7)
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# now our queue should look like [5, 7]
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print(f"queue after enqueueing 7: {exampleFIFO.arr}")
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exampleFIFO.enqueue(8)
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# now our queue should look like [5, 7, 8]
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print(f"queue after enqueueing 8: {exampleFIFO.arr}")
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# front
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print(f"If we try looking at the front of the queue we get: {exampleFIFO.front()}")
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#rear
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print(f"If we try looking at the rear of the queue we get: {exampleFIFO.rear()}")
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