1.题目要求:
2.题目代码:
csharp
/**
* 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:
//设置vector容器,输入树结点的值
vector<int> tree_val;
//设置迭代的下标
int i;
void inorder_travel(TreeNode* root){
if(root == NULL){
return;
}
inorder_travel(root->left);
tree_val.push_back(root->val);
inorder_travel(root->right);
}
BSTIterator(TreeNode* root) {
//采用中序遍历存入节点值
inorder_travel(root);
i = -1;
}
int next() {
//迭代一次,返回值
this->i++;
return tree_val[i];
}
bool hasNext() {
//判断数组是否超限
if(i + 1 >= tree_val.size()){
return false;
}else{
return true;
}
}
};
/**
* 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();
*/