按头和尾输入线性表各数据元素的值，建立两个链表。分别删除将两个链表中值最大和最小的结点，要求给出C/C++代码

在C++中，我们可以创建一个双向链表节点结构，并编写函数来实现按头和尾插入元素、删除最大和最小值的节点。首先，我们定义一个双向链表节点：

template <typename T>
struct ListNode {
    T value;
    ListNode* prev;
    ListNode* next;
    ListNode(T val) : value(val), prev(nullptr), next(nullptr) {}
};

接下来，我们定义一些操作链表的函数：

1. 插入头节点：

void insertAtHead(ListNode<T>* &list, const T& value) {
    ListNode<T> *newNode = new ListNode<T>(value);
    newNode->next = list;
    if (list != nullptr)
        list->prev = newNode;
    list = newNode;
}

2. 插入尾节点：

void insertAtTail(ListNode<T>** &head, const T& value) {
    ListNode<T> *newNode = new ListNode<T>(value);
    if (*head == nullptr) {
        *head = newNode;
        return;
    }
    ListNode<T> *last = *head;
    while (last->next != nullptr)
        last = last->next;
    last->next = newNode;
    newNode->prev = last;
}

3. 删除最大值节点：

ListNode<T>* deleteMaxNode(ListNode<T>** head) {
    if (*head == nullptr || (*head)->next == nullptr)
        return *head;

    ListNode<T>* maxNode = *head;
    for (ListNode<T> *current = *head; current->next != nullptr; current = current->next) {
        if (current->value > maxNode->value)
            maxNode = current;
    }

    if (maxNode == *head) {
        *head = maxNode->next;
        if (*head)
            (*head)->prev = nullptr;
    } else {
        maxNode->prev->next = maxNode->next;
        if (maxNode->next)
            maxNode->next->prev = maxNode->prev;
    }

    delete maxNode;
    return nullptr;
}

4. 删除最小值节点：

ListNode<T>* deleteMinNode(ListNode<T>** tail) {
    if (*tail == nullptr || (*tail)->prev == nullptr)
        return *tail;

    ListNode<T>* minNode = *tail;
    for (ListNode<T> *current = *tail; current->prev != nullptr; current = current->prev) {
        if (current->value < minNode->value)
            minNode = current;
    }

    if (minNode == *tail) {
        *tail = minNode->prev;
        if (*tail)
            (*tail)->next = nullptr;
    } else {
        minNode->next->prev = minNode->prev;
        if (minNode->prev)
            minNode->prev->next = minNode->next;
    }

    delete minNode;
    return nullptr;
}