def test1():
"""
测试栈
:return:
"""
stack = Stack()
stack.push(3)
stack.push(6)
stack.push(9)
stack.push(12)
# 12,9,6,3,
print(stack)
# 12
print(stack.pop())
# 9,6,3,
print(stack)
# 9
print(stack.top())
def inorder_traversal(self) -> List[T]:
"""
中序遍历
:return:
"""
if self._root is None:
return
container = []
stack = Stack()
curr = self._root
while curr or not stack.is_empty():
if curr is not None:
stack.push(curr)
curr = curr.left
else:
node = stack.pop()
container.append(node.element)
curr = node.right
return container
def preorder_traversal(self) -> List[T]:
"""
前序
:return:
"""
if self._root is None:
return []
container = []
stack = Stack()
stack.push(self._root)
while not stack.is_empty():
node = stack.pop()
container.append(node.element)
# if cmp(node.element): break
if node.right is not None:
stack.push(node.right)
if node.left is not None:
stack.push(node.left)
return container
def postorder_traversal(self) -> List[T]:
"""
后序遍历
:return:
"""
if self._root is None:
return
container = []
stack = Stack()
stack.push(self._root)
prev = None
while not stack.is_empty():
# 取出栈最顶端的元素
node = stack.top()
if node.is_leaf() or (prev and prev.parent == node):
prev = stack.pop()
container.append(prev.element)
else:
if node.right is not None:
stack.push(node.right)
if node.left is not None:
stack.push(node.left)
return container
from com.jqc.stack.stack import Stack
if __name__ == '__main__':
# test1()
# test2()
# test3()
stack = Stack()
stack.push(3)
stack.push(6)
stack.push(9)
stack.push(12)
# 12,9,6,3,
print(stack)
# 12
print(stack.pop())
# 9,6,3,
print(stack)
# 9
print(stack.top())