设计一组整数，完成链表（带表头结点）的基本操作。建立链表、插入、删除、查找、输出、求前驱、求后继、两个有序链表的合并操作。 其他基本操作还有销毁链表、将链表置为空表、求链表的长度、获取某位置结点的内容、搜索结点、销毁等。

链表基本操作的实现：

1. 建立链表

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

Node *createList() {
    Node *head = (Node *)malloc(sizeof(Node));
    head->next = NULL;
    return head;
}

2. 插入

void insert(Node *head, int data) {
    Node *p = (Node *)malloc(sizeof(Node));
    p->data = data;
    p->next = head->next;
    head->next = p;
}

3. 删除

void remove(Node *head, int data) {
    Node *p = head->next;
    Node *pre = head;
    while (p != NULL) {
        if (p->data == data) {
            pre->next = p->next;
            free(p);
            break;
        }
        pre = p;
        p = p->next;
    }
}

4. 查找

Node *find(Node *head, int data) {
    Node *p = head->next;
    while (p != NULL) {
        if (p->data == data) {
            return p;
        }
        p = p->next;
    }
    return NULL;
}

5. 输出

void printList(Node *head) {
    Node *p = head->next;
    while (p != NULL) {
        printf("%d ", p->data);
        p = p->next;
    }
    printf("\n");
}

6. 求前驱

Node *getPre(Node *head, int data) {
    Node *p = head->next;
    Node *pre = head;
    while (p != NULL) {
        if (p->data == data) {
            return pre;
        }
        pre = p;
        p = p->next;
    }
    return NULL;
}

7. 求后继

Node *getNext(Node *head, int data) {
    Node *p = head->next;
    while (p != NULL && p->data != data) {
        p = p->next;
    }
    if (p != NULL) {
        return p->next;
    }
    return NULL;
}

8. 合并有序链表

Node *mergeList(Node *head1, Node *head2) {
    Node *p1 = head1->next;
    Node *p2 = head2->next;
    Node *head = createList();
    Node *p = head;

    while (p1 != NULL && p2 != NULL) {
        if (p1->data < p2->data) {
            p->next = p1;
            p1 = p1->next;
        } else {
            p->next = p2;
            p2 = p2->next;
        }
        p = p->next;
    }

    if (p1 != NULL) {
        p->next = p1;
    }
    if (p2 != NULL) {
        p->next = p2;
    }

    return head;
}

9. 销毁链表

void destroyList(Node *head) {
    Node *p = head->next;
    while (p != NULL) {
        Node *tmp = p;
        p = p->next;
        free(tmp);
    }
    head->next = NULL;
}

10. 将链表置为空表

void clearList(Node *head) {
    destroyList(head);
}

11. 求链表的长度

int length(Node *head) {
    int len = 0;
    Node *p = head->next;
    while (p != NULL) {
        len++;
        p = p->next;
    }
    return len;
}

12. 获取某位置结点的内容

int get(Node *head, int index) {
    Node *p = head->next;
    int i = 0;
    while (p != NULL && i < index) {
        p = p->next;
        i++;
    }
    if (p != NULL) {
        return p->data;
    }
    return -1;
}

13. 搜索结点

bool search(Node *head, int data) {
    Node *p = head->next;
    while (p != NULL) {
        if (p->data == data) {
            return true;
        }
        p = p->next;
    }
    return false;
}

14. 销毁

void destroy(Node *head) {
    free(head);
}