题目链接:点击这里
/**
* 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:
void inorder(TreeNode* r, vector<int>& v)
{
if(r!=NULL)
{
inorder(r->left, v);
v.push_back(r->val);
inorder(r->right, v);
}
}
int kthSmallest(TreeNode* root, int k) {
vector<int> v;
inorder(root, v);
return v[k-1];
}
};