以下代码实现了二叉树的中序遍历。输入以下二叉树，中序遍历结果是 4 2 5 1 3 6。

//     1
//    / \
//   2   3
//  / \   \
// 4   5   6

struct TreeNode {
    int val;
    TreeNode* left;
    TreeNode* right;
    TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
};

void inorderIterative(TreeNode* root) {
    stack<TreeNode*> st;
    TreeNode* curr = root;

    while (curr || !st.empty()) {
        while (curr) {
            st.push(curr);
            curr = curr->left;
        }
        curr = st.top(); st.pop();
        cout << curr->val << " ";
        curr = curr->right;
    }
}

{{ select(1) }}

• 正确
• 错误