标签：style blog color io ar java for strong sp
Two elements of a binary search tree (BST) are swapped by mistake.
Recover the tree without changing its structure.
Note:confused what "{1,#,2,3}" means?
The serialization of a binary tree follows a level order traversal, where ‘#‘ signifies a path terminator where no node exists below.
Here‘s an example:
1
/ 2 3
/
4
5
The above binary tree is serialized as "{1,2,3,#,#,4,#,#,5}".
/**
* Definition for binary tree
* public class TreeNode {
* int val;
* TreeNode left;
* TreeNode right;
* TreeNode(int x) { val = x; }
* }
*/
public class Solution {
TreeNode a=null;
TreeNode b=null;
TreeNode pre;
public void recover(TreeNode root)
{
if(root!=null)
{
recover(root.left);
if(pre.val>root.val)
{
if(a==null)
{
a=pre;
}
b=root;
}
pre=root;
recover(root.right);
}
}
public void recoverTree(TreeNode root) {
pre=new TreeNode(Integer.MIN_VALUE);
recover(root);
if(a!=null)
{
int p=a.val;
a.val=b.val;
b.val=p;
}
}
}标签：style blog color io ar java for strong sp
原文地址：http://blog.csdn.net/jiewuyou/article/details/40183587
