C++ 有没有办法实现这个二叉搜索树功能

我正在努力实现以下功能:

给定一个二叉搜索树，返回最小的 node ，然后将指针移动到树中下一个最小的 node .在再次调用该函数时，它应该返回下一个最小的 node ，依此类推.

任何帮助都将不胜感激.

这是我到目前为止的程序，其中包含一些辅助函数及其定义:

#include <stdio.h>
#include <stdlib.h>
 
/* A binary tree node has data,
   the pointer to left child
   and a pointer to right child */
struct node {
    int data;
    struct node *left;
    struct node *right;
    struct node *parent;
};
 
struct node *minValue(struct node *node);
 
struct node *inOrderSuccessor(
    struct node *root,
    struct node *n)
{
    if (n->right != NULL)
        return minValue(n->right);
   
    struct node *p = n->parent;
    while (p != NULL && n == p->right) {
        n = p;
        p = p->parent;
    }
    return p;
}
 
/* Given a non-empty binary search tree,
    return the minimum data 
    value found in that tree. Note that
    the entire tree does not need
    to be searched. */
struct node *minValue(struct node *node)
{
    struct node *current = node;
 
    /* loop down to find the leftmost leaf */
    while (current->left != NULL) {
        current = current->left;
    }
    return current;
}
 
/* Helper function that allocates a new
    node with the given data and
    NULL left and right pointers. */
struct node *newNode(int data)
{
    struct node *node = (struct node *)malloc(sizeof(struct node));
    node->data = data;
    node->left = NULL;
    node->right = NULL;
    node->parent = NULL;
 
    return (node);
}
 
/* Give a binary search tree and
   a number, inserts a new node with   
    the given number in the correct
    place in the tree. Returns the new
    root pointer which the caller should
    then use (the standard trick to
    avoid using reference parameters). */
struct node *insert(struct node *node,
                    int data)
{
    /* 1. If the tree is empty, return a new,
      single node */
    if (node == NULL)
        return (newNode(data));
    else {
        struct node *temp;
 
        /* 2. Otherwise, recur down the tree */
        if (data <= node->data) {
            temp = insert(node->left, data);
            node->left = temp;
            temp->parent = node;
        } else {
            temp = insert(node->right, data);
            node->right = temp;
            temp->parent = node;
        }
 
        /* return the (unchanged) node pointer */
        return node;
    }
}