[数据结构与算法]C语言升序单向链表的创建，插入删除操作，代码经过验证

#include <stdio.h>
#include <stdlib.h>

typedef struct n {
    int data;
    struct n* pre;
    struct n* next;    
}*node;

node create_node();
void print(node head);
node insert(node head, int i);
node deleteNode(node head, int i);

int main() 
{
    // 链表的建立、插入、删除、打印操作
    node head = create_node();
    print(head);
    head = insert(head, 11);
    print(head);
    head = deleteNode(head, 9);
    print(head);
}

// 创建链表
node create_node()
{
    node head, p, s;
    int x;
    head = (node)malloc(sizeof(struct n));  //创建一个头结点
    p = head;

    while(scanf("%d", &x)&&x) {
        s = (node)malloc(sizeof(struct n));
        s->data = x;
        s->pre = p;
        p->next = s;

        p = s;
    }
    
    p->next = NULL;
    head = head->next;
    head->pre = NULL;

    return head;
}

// 打印节点
void print(node head) {
    node p;
    p = head;
    printf("正序输出链表：\n");
    while(p) {
        printf("%d ",p->data);
        p = p->next;
    }
    printf("\n");
}

// 插入一个节点
node insert(node head, int i) {
    node temp = (node)malloc(sizeof(struct n));
    temp->data = i;
    node p = head;
    if(i < p->data) {
        temp->next = p;
        temp->pre = NULL;
        p->pre = temp;
        return temp;
    }

    while(p->next && i>p->data) {     // 寻找合适的位置插入
        p = p->next;
    }

    if(i <= p->data) {                 // 在链表的中间某处插入
        temp->next = p;
        temp->pre = p->pre;
        p->pre->next = temp;
        p->pre = temp;
    } else {                    // 没有找到合适的位置，插入到链表尾部
        p->next = temp;
        temp->pre = p;
        temp->next = NULL;
    }
    return head;
}

// 删除一个节点
node deleteNode(node head, int i) {
    node p = head;
    
    // 如果头结点是要删除的节点
    if(i == p->data) {
        head = head->next;
        p->next = NULL;
        head->pre = NULL;
        free(p);
        return head;
    }

    // 定位到链表上的节点
    while(p && i!=p->data) {
        p = p->next;
    }

    if(p && i==p->data) {
        p->pre->next = p->next;
        p->next->pre = p->pre;
        free(p);
    } else {
        printf("delete error\n");
    }
    return head;
}