链表输入n个学生成绩，删除最高成绩，删除最低成绩，计算平均值代码

首先，我们需要定义链表的节点结构以及链表的基本操作，包括插入、删除和计算平均值的函数。下面是一个简单的Python代码示例，实现插入学生成绩到链表、删除最高成绩、删除最低成绩以及计算平均值的功能：

class ListNode:
    def __init__(self, val=0, next=None):
        self.val = val
        self.next = next

def insert_scores(head, scores):
    # 创建一个哨兵节点作为链表的起始节点
    sentinel = ListNode()
    current = sentinel
    for score in scores:
        current.next = ListNode(score)
        current = current.next
    # 更新头节点为实际的第一个节点
    head = sentinel.next
    return head

def delete_max(head):
    if not head:
        return None
    if not head.next:
        return None
    # 最大值节点和前驱节点初始化
    max_node = head
    prev_max = None
    current = head.next
    current_prev = head
    while current:
        if current.val > max_node.val:
            max_node = current
            prev_max = current_prev
        current_prev = current
        current = current.next
    # 删除最大值节点
    prev_max.next = max_node.next
    return head

def delete_min(head):
    if not head:
        return None
    if not head.next:
        return None
    # 最小值节点和前驱节点初始化
    min_node = head
    prev_min = None
    current = head.next
    current_prev = head
    while current:
        if current.val < min_node.val:
            min_node = current
            prev_min = current_prev
        current_prev = current
        current = current.next
    # 删除最小值节点
    prev_min.next = min_node.next
    return head

def calculate_average(head):
    if not head:
        return 0
    total = 0
    count = 0
    current = head
    while current:
        total += current.val
        count += 1
        current = current.next
    return total / count if count else 0

# 使用示例
scores = [70, 80, 90, 100, 50]
head = None
head = insert_scores(head, scores)
head = delete_max(head)
head = delete_min(head)
average = calculate_average(head)
print(f"删除最高和最低成绩后的平均分是: {average}")

这段代码中，我们首先定义了一个链表节点类`ListNode`，然后定义了`insert_scores`函数用于将成绩插入到链表中，`delete_max`和`delete_min`函数用于删除链表中的最高和最低成绩节点，`calculate_average`函数用于计算链表中所有成绩的平均值。