Leetcode:binary Tree inorder Traversal Problem Solving report

Binary Tree inorder Traversal

Given a binary tree, return the inorder traversal of its nodes ' values.

For example:
Given binary Tree {1,#,2,3},
1
\
2
/
3
return [1,3,2].

Note:recursive solution is trivial, could do it iteratively?

Confused what "{1,#,2,3}" means? > read more about how binary tree was serialized on OJ.

SOL:

Includes recursive and non-recursive methods:

1 /**2 * Definition for binary tree3 * public class TreeNode {4 * int val;5 * TreeNode left;6 * TreeNode right;7 * TreeNode (int x) {val = x;}8  * }9  */Ten  Public classSolution { One      PublicList<integer>inorderTraversal1 (TreeNode root) { Alist<integer> ret =NewArraylist<integer>(); - Rec (root, ret); -         returnret; the     } -      -      Public voidRec (TreeNode root, list<integer>ret) { -         if(Root = =NULL) { +             return; -         } +          A Rec (root.left, ret); at Ret.add (root.val); - Rec (root.right, ret); -     } -      -      PublicList<integer>inordertraversal (TreeNode root) { -list<integer> ret =NewArraylist<integer>(); in         if(Root = =NULL) { -             returnret; to         } +          -stack<treenode> s =NewStack<treenode>(); theTreeNode cur =Root; *          $          while(true) {Panax Notoginseng              while(cur! =NULL) { - s.push (cur); theCur =Cur.left; +             } A              the             if(S.isempty ()) { +                  Break; -             } $              $Cur =S.pop (); - Ret.add (cur.val); -              theCur =Cur.right; -         }Wuyi          the         returnret; -     } Wu}

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Leetcode:binary Tree inorder Traversal Problem Solving report