/**
* Definition for a binary tree node.
* struct TreeNode {
* int val;
* TreeNode *left;
* TreeNode *right;
* TreeNode(int x) : val(x), left(NULL), right(NULL) {}
* };
*/
class Solution {
public:
TreeNode* searchBST(TreeNode* root, int val) {
if(root->val==val)return root;
TreeNode* p;
p = root;
while(p!=NULL&&p->val!=val)
{
if(p->val>val)p=p->left;
else if(p->valright;
}
return p;
}
};