94. 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]

.

递归喽

public class Solution {
public List<Integer> inorderTraversal(TreeNode root) {
List<Integer> result = new ArrayList<Integer>();
List<Integer> left = new ArrayList<Integer>();
List<Integer> right = new ArrayList<Integer>();
if (root == null) {
return result;
}
left = inorderTraversal(root.left);
right = inorderTraversal(root.right);
result.addAll(left);
result.add(root.val);
result.addAll(right);
return result;
}
}