顺序表的基本操作代码C++

在C++中，顺序表是一种线性的数据结构，它通过连续的内存地址存储元素。基本的操作通常包括插入、删除和访问元素。这里是一个简单的顺序表实现示例，使用数组作为底层存储：

#include <iostream>

// 定义顺序表节点
struct ListNode {
    int data;
    ListNode* next; // 指向下一个元素的指针
};

// 初始化顺序表
ListNode* createList() {
    return nullptr; // 初始为空列表
}

// 在列表末尾添加元素
void append(ListNode*& head, int value) {
    ListNode* newNode = new ListNode{value, nullptr};
    if (head == nullptr) { // 如果列表为空
        head = newNode;
    } else {
        ListNode* current = head;
        while (current->next != nullptr) {
            current = current->next;
        }
        current->next = newNode;
    }
}

// 删除指定值的第一个匹配项
void removeElement(ListNode*& head, int value) {
    if (head == nullptr) {
        return;
    }

    if (head->data == value) {
        ListNode* temp = head;
        head = head->next;
        delete temp;
        return;
    }

    ListNode* current = head;
    while (current->next != nullptr && current->next->data != value) {
        current = current->next;
    }
    if (current->next != nullptr) {
        current->next = current->next->next;
        delete current->next;
    }
}

// 访问指定索引的元素
int accessElement(const ListNode* head, size_t index) {
    if (index >= head->next == nullptr) {
        std::cerr << "Index out of range.\n";
        return -1;
    }

    ListNode* current = head;
    for (size_t i = 0; i < index; ++i) {
        current = current->next;
    }
    return current->data;
}

// 示例：创建并操作顺序表
int main() {
    ListNode* list = createList();
    append(list, 1);
    append(list, 2);
    append(list, 3);

    std::cout << "List: ";
    ListNode* temp = list;
    while (temp != nullptr) {
        std::cout << temp->data << " ";
        temp = temp->next;
    }
    std::cout << "\n";

    removeElement(list, 2);
    std::cout << "After removing 2: ";
    temp = list;
    while (temp != nullptr) {
        std::cout << temp->data << " ";
        temp = temp->next;
    }
    std::cout << "\n";

    std::cout << "Element at index 1: " << accessElement(list, 1) << "\n";

    return 0;
}