算法
先存起来
参考文献
C++ 代码
/**
* Definition for a binary tree node.
* struct TreeNode {
* int val;
* TreeNode *left;
* TreeNode *right;
* TreeNode() : val(0), left(nullptr), right(nullptr) {}
* TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
* TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
* };
*/
class BSTIterator {
public:
int pos;
vector<int> ans;
void inorder(TreeNode *r)
{
if(r)
{
inorder(r->left);
ans.push_back(r->val);
inorder(r->right);
}
}
BSTIterator(TreeNode* root) {
inorder(root);
pos = 0;
}
int next() {
return ans[pos++];
}
bool hasNext() {
return pos < ans.size();
}
};
/**
* Your BSTIterator object will be instantiated and called as such:
* BSTIterator* obj = new BSTIterator(root);
* int param_1 = obj->next();
* bool param_2 = obj->hasNext();
*/