@@ -371,25 +371,57 @@ class Solution {
371371Python:
372372``` Python
373373class Solution :
374+ """ 二叉树的所有路径 递归法"""
375+ 374376 def binaryTreePaths (self root : TreeNode) -> List[str ]:
375- path= []
376- res= []
377- def backtrace (root , path ):
378- if not root:return
379- path.append(root.val)
380- if (not root.left)and (not root.right):
381- res.append(path[:])
382- ways= []
383- if root.left:ways.append(root.left)
384- if root.right:ways.append(root.right)
385- for way in ways:
386- backtrace(way,path)
387- path.pop()
388- backtrace(root,path)
389- return [" ->" list (map (str ,i))) for i in res]
377+ path, result = ' '
378+ self .traversal(root, path, result)
379+ return result
380+ 381+ def traversal (self cur : TreeNode, path : List, result : List):
382+ path += str (cur.val)
383+ # 如果当前节点为叶子节点,添加路径到结果中
384+ if not (cur.left or cur.right):
385+ result.append(path)
386+ return
387+ 388+ if cur.left:
389+ self .traversal(cur.left, path + ' ->'
390+ 391+ if cur.right:
392+ self .traversal(cur.right, path + ' ->'
393+ 394+ ```
395+ 396+ ``` python
397+ from collections import deque
390398
399+ 400+ class Solution :
401+ """ 二叉树的所有路径 迭代法"""
402+ 403+ def binaryTreePaths (self root : TreeNode) -> List[str ]:
404+ # 题目中节点数至少为1
405+ stack, path_st, result = deque([root]), deque(), []
406+ path_st.append(str (root.val))
407+ 408+ while stack:
409+ cur = stack.pop()
410+ path = path_st.pop()
411+ # 如果当前节点为叶子节点,添加路径到结果中
412+ if not (cur.left or cur.right):
413+ result.append(path)
414+ if cur.right:
415+ stack.append(cur.right)
416+ path_st.append(path + ' ->' + str (cur.right.val))
417+ if cur.left:
418+ stack.append(cur.left)
419+ path_st.append(path + ' ->' + str (cur.left.val))
420+ 421+ return result
391422```
392423
424+ 393425Go:
394426``` go
395427func binaryTreePaths (root *TreeNode ) []string {
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