[语法]删除与插入链表节点

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

struct Student
{
    int id;
    char name[16];
    Student* next;
};

// 定义了一个有头节点
Student m_head = {0};

// 按顺序插入节点
int insert(Student* obj)
{
    Student* cur = m_head.next; // 当前节点current
    Student* pre = &m_head;  // 上一个节点previous
    while(cur)
    {		
        if(obj->id < cur->id) // 找到这个位置
            break;

        pre = cur;
        cur = cur->next;  // 找到最后一个对象
    }

    // 插入到pre节点的后面
    obj->next = pre->next;
    pre->next = obj;
    return 0;
}

// 按id查找并删除节点
void remove(int id)
{
    Student* cur = m_head.next; // 当前节点current
    Student* pre = &m_head;  // 上一个节点previous
    while(cur)
    {		
        if(id == cur->id) // 找到这个位置
        {
            // 删除该节点
            pre->next = cur->next;
            free(cur);
            break;
        }
        pre = cur;
        cur = cur->next;  // 找到最后一个对象
    }
}

// 遍历
void show_all()
{
    Student* p = m_head.next; 
    while(p)
    {
        printf("ID: %d, name: %s\n", p->id, p->name);
        p = p->next; // 下一个对象
    }
}

int main()
{
    Student* obj = NULL;
    

    obj = (Student*)malloc (sizeof(Student));
    obj->id = 8;
    strcpy(obj->name, "888");
    insert(obj);

    obj = (Student*)malloc (sizeof(Student));
    obj->id = 1;
    strcpy(obj->name, "111");
    insert(obj);

    obj = (Student*)malloc (sizeof(Student));
    obj->id = 4;
    strcpy(obj->name, "444");
    insert(obj);

    obj = (Student*)malloc (sizeof(Student));
    obj->id = 3;
    strcpy(obj->name, "333");
    insert(obj);

    obj = (Student*)malloc (sizeof(Student));
    obj->id = 5;
    strcpy(obj->name, "555");
    insert(obj);

    remove(3);
    remove(2);
    show_all();
    return 0;
}