12 lines
271 B
Python
12 lines
271 B
Python
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from collections import deque
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class Stack:
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def __init__(self):
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self._items = deque()
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def append(self, item):
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self._items.append(item)
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def pop(self):
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return self._items.pop()
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def __nonzero__(self):
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return bool(self._items)
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