22 lines
510 B
Python
22 lines
510 B
Python
class Stack:
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def __init__(self):
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self.stack = []
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def push(self, item):
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self.stack.append(item)
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def pop(self):
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if not self.is_empty():
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return self.stack.pop()
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raise IndexError("pop from empty stack")
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def peek(self):
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if not self.is_empty():
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return self.stack[-1]
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raise IndexError("peek from empty stack")
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def is_empty(self):
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return len(self.stack) == 0
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def size(self):
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return len(self.stack) |