ring_buffer.py

(Hello, so I'me pretty sure the code is correct except for the enqueue and the dequeue sections. I tried my best to get it to work but am stuck. I attached my code as well as the details given to us as to how to create this sequence. Please use the format the code is already, using the given imported modules, and thank you in advance.)

(the picture file was a bit blurry so I also copied the text I had directly)

""" ring_buffer.py Models a ring buffer. """ import stdarray import stdio import sys def create(capacity): """ Create and return a ring buffer, with the given maximum capacity and with all elements initialized to None. A ring buffer is represented as a list of four elements: the buffer (buff) itself as a list; number of elements (size) currently in buff; the index (first) of the least recently inserted item; and the index (last) one beyond the most recently inserted item. """ buff = stdarray.create1D(capacity, None) size = 0 first = 0 last = 0 rb = [buff, size, first, last] def capacity(rb): """ Return the capacity of the ring buffer. """ capacity_rb = len(rb[0]) return capacity_rb def size(rb): """ Return the number of items currently in the buffer rb. """ size_rb = rb[1] return size_rb def is_empty(rb): """ Return True if the buffer rb is empty and False otherwise. """ if (size(rb) == 0): return True else: return False def is_full(rb): """ Return True if the buffer rb is full and False otherwise. """ if (size(rb) == capacity(rb)): return True else: return False def enqueue(rb, x): """ Add item x to the end of the buffer rb. """ x = rb[3] if (last + 1) == capacity: last = 0 else: last += 1 last += 1 def dequeue(rb): """ Delete and return item from the front of the buffer rb. """ v = rb[2] if (first + 1) == capacity: first = 0 else: first += 1 first += -1 return v def peek(rb): """ Return (but do not delete) item from the front of the buffer rb. """ peek_rb = rb[0] return peek_rb def _main(): """ Test client [DO NOT EDIT]. """ N = int(sys.argv[1]) rb = create(N) for i in range(1, N + 1): enqueue(rb, i) t = dequeue(rb) enqueue(rb, t) stdio.writef('Size after wrap-around is %d ', size(rb)) while size(rb) >= 2: x = dequeue(rb) y = dequeue(rb) enqueue(rb, x + y) stdio.writeln(peek(rb)) if __name__ == '__main__': _main()

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(Below is the given guidelines for each section)

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