优化Python递归时所需要的内存开销和时间消耗。

This commit is contained in:
zhangchang
2024-02-24 22:46:14 +08:00
parent 095242f4b7
commit b4f55e7274

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@ -180,26 +180,34 @@ class Solution {
class Solution: class Solution:
def preorderTraversal(self, root: TreeNode) -> List[int]: def preorderTraversal(self, root: TreeNode) -> List[int]:
if not root: res = []
return []
def dfs(node):
left = self.preorderTraversal(root.left) if node is None:
right = self.preorderTraversal(root.right) return
return [root.val] + left + right res.append(node.val)
dfs(node.left)
dfs(node.right)
return res
``` ```
```python ```python
# 中序遍历-递归-LC94_二叉树的中序遍历 # 中序遍历-递归-LC94_二叉树的中序遍历
class Solution: class Solution:
def inorderTraversal(self, root: TreeNode) -> List[int]: def inorderTraversal(self, root: TreeNode) -> List[int]:
if root is None: res = []
return []
def dfs(node):
left = self.inorderTraversal(root.left) if node is None:
right = self.inorderTraversal(root.right) return
return left + [root.val] + right dfs(node.left)
res.append(node.val)
dfs(node.right)
return res
``` ```
```python ```python
@ -207,13 +215,17 @@ class Solution:
# 后序遍历-递归-LC145_二叉树的后序遍历 # 后序遍历-递归-LC145_二叉树的后序遍历
class Solution: class Solution:
def postorderTraversal(self, root: TreeNode) -> List[int]: def postorderTraversal(self, root: TreeNode) -> List[int]:
if not root: res = []
return []
def dfs(node):
left = self.postorderTraversal(root.left) if node is None:
right = self.postorderTraversal(root.right) return
return left + right + [root.val] dfs(node.left)
dfs(node.right)
res.append(node.val)
return res
``` ```
### Go ### Go