LeetCode OJ-- Recover Binary Search Tree ***@

https://oj.leetcode.com/problems/recover-binary-search-tree/

一棵二叉搜索树，二叉搜索树的特征是，中根遍历的话，得到的序列是递增的

题目中，有两个节点弄混了，让恢复这个二叉搜索树

class Solution {
public:
TreeNode *LastNode = new TreeNode(INT_MIN);

void recoverTree(TreeNode *root) {
if(root == NULL)
return;

TreeNode **n1 = (TreeNode**)malloc(sizeof(TreeNode*));
TreeNode **n2 = (TreeNode**)malloc(sizeof(TreeNode*));
*n1 = NULL;
*n2 = NULL;
find(root,n1,n2);
//swap
int temp;
temp = (*n1)->val; (*n1)->val = (*n2)->val; (*n2)->val = temp;
}

//中根遍历
void find(TreeNode *root, TreeNode **n1, TreeNode **n2)
{
if(root == NULL)
return;

find(root->left,n1,n2);

//分别处理了是 2 1 还是，3 2 1 的情况，高！
if(*n1 == NULL && root->val < LastNode->val)
{
*n1 = LastNode;
}
if(*n1 != NULL && root->val < LastNode->val)
{
*n2 = root;
}

LastNode = root;

find(root->right,n1,n2);
}
};