写一下单链表基本操作删除操作的代码

在单链表中，删除一个节点通常需要处理两种情况：删除头节点和删除非头节点。这里我会给出两个示例，分别是使用指针在C++和Python中的实现：

**C++ 示例（使用迭代法）：**

#include <iostream>

struct Node {
    int data;
    Node* next;
};

// 删除头节点
Node* deleteFirst(Node* head) {
    if (head == nullptr) return nullptr; // 如果链表为空
    Node* temp = head;
    head = head->next;
    delete temp; // 释放原头节点
    return head;
}

// 删除指定位置的节点（假设已知节点值）
Node* deleteNodeByValue(Node* head, int value) {
    if (head == nullptr) return nullptr;

    Node* prev = nullptr;
    Node* curr = head;

    while (curr != nullptr && curr->data != value) {
        prev = curr;
        curr = curr->next;
    }

    if (curr == nullptr) return head; // 没找到要删除的节点

    if (prev == nullptr) head = curr->next; // 删除头节点
    else prev->next = curr->next; // 删除中间节点
    delete curr; // 释放内存
    return head;
}

**Python 示例：**

class Node:
    def __init__(self, data=None, next=None):
        self.data = data
        self.next = next

# 删除头节点
def delete_first(head):
    if not head:
        return None
    head = head.next
    del head  # Python中直接删除对象
    return head

# 删除指定值的节点
def delete_node_by_value(head, value):
    if not head:
        return head
    current = head
    previous = None
    while current and current.data != value:
        previous = current
        current = current.next
    if current is None:
        return head
    if previous is None:
        head = current.next
    else:
        previous.next = current.next
    del current  # Python中直接删除对象
    return head