给定一棵二叉树,使用非递归的方式实现二叉树左右子树交换,并输出中序遍历结果
时间: 2024-01-23 19:42:53 浏览: 27
可以使用栈来实现二叉树的非递归遍历,具体实现过程如下:
1. 创建一个栈,将根节点入栈
2. 循环执行以下操作:
- 取出栈顶节点,并交换其左右子树
- 如果该节点有右子树,则右子树入栈
- 如果该节点有左子树,则左子树入栈
3. 当栈为空时,遍历结束
下面是代码实现:
```python
class TreeNode:
def __init__(self, val):
self.val = val
self.left = None
self.right = None
def invertedTree(root):
stack = []
if not root:
return
stack.append(root)
while stack:
node = stack.pop()
node.left, node.right = node.right, node.left
if node.right:
stack.append(node.right)
if node.left:
stack.append(node.left)
def inOrder(root):
if not root:
return []
res = []
stack = []
node = root
while node or stack:
while node:
stack.append(node)
node = node.left
node = stack.pop()
res.append(node.val)
node = node.right
return res
# 测试代码
if __name__ == '__main__':
root = TreeNode(1)
root.left = TreeNode(2)
root.right = TreeNode(3)
root.left.left = TreeNode(4)
root.left.right = TreeNode(5)
root.right.left = TreeNode(6)
root.right.right = TreeNode(7)
print('交换前的中序遍历结果:', inOrder(root))
invertedTree(root)
print('交换后的中序遍历结果:', inOrder(root))
```
输出结果:
```
交换前的中序遍历结果: [4, 2, 5, 1, 6, 3, 7]
交换后的中序遍历结果: [7, 3, 6, 1, 5, 2, 4]
```