def pop(self):
if self.is_empty():
raise Empty("Stack is empty")
e = self._data[self._index - 1]
self._data[self._index - 1] = None
self._index -= 1
return e
def peek(self):
"""Return but do not remove the element off the top of the stack
:returns Element on the top of the stack
"""
if self.is_empty():
raise Empty("Stack is empty")
return self._data[self._size - 1]
def pop(self):
"""Pop the element off the top of the stack
:returns Element on the top of the stack
"""
if self.is_empty():
raise Empty("Stack is empty!")
e = self._data[self._size-1]
self._data[self._size-1] = None
self._min[self._size-1] = None
self._size -= 1
self._min.pop()
return e
def peek(self, s):
"""Return but do not pop the top element off the top of the stack s
:param s Stack number (1-3)
:returns Reference to the element on the top of the stack s
"""
if s not in range(1, 4):
raise IOError(str(s) + " not in valid stack range (1-3)")
if self.stacks[s - 1].is_empty():
raise Empty("Stack is empty!")
index = self._get_stack_index_reference(s) - 1
return self.data[index]
def pop(self):
"""Pop the first element off the first non-empty stack
:returns Element off the top of the first non-empty stack
"""
index = 0
popped = False
while index < len(self._stacks) and not popped:
if not self._stacks[index].is_empty():
e = self._stacks[index].pop()
popped = True
else:
index += 1
if not popped:
raise Empty("All stacks are empty")
return e
def pop(self, s):
"""Pop the element off the top of the stack s
:param s Stack number (1-3)
:returns The reference to the element at the top of the stack s
"""
if s not in range(1, 4):
raise IOError(str(s) + " not in valid stack range (1-3)")
if self.stacks[s - 1].is_empty():
raise Empty("Stack is empty!")
index = self._get_stack_index_reference(s) - 1
e = self.data[index]
self.data[index] = None
self.stacks[s - 1].index -= 1
return e
def peek(self):
if self.is_empty():
raise Empty("Stack is empty")
return self._data[self._index - 1]