Design of C language employee management system

#include<>
#include<>
#include <>
struct Worker
{
 int id;//Work number char name[16];//Name char sex[8];//gender int age;//age char edu_exp[32];//Education int wage;//salary char adress[32];//address char phong[16];//Telephone Worker* next;
};
//Create the table headerWorker m_head = { 0 };
//User input informationint user_input(Worker* w)
{
 printf("ID:");
 scanf("%d", &w->id);
 getchar();//Absorb the carriage return characters printf("name:");
 gets_s(w->name);
 printf("sex:");
 gets_s(w->sex);
 printf("age:");
 scanf("%d", &w->age);
 getchar();//Absorb the carriage return characters printf("edu_exp:");
 gets_s(w->edu_exp);
 printf("wage:");
 scanf("%d", &w->wage);
 getchar();//Absorb the carriage return characters printf("adress:");
 gets_s(w->adress);
 printf("phone:");
 gets_s(w->phong);

 return 0;
}
//Add an objectvoid add(Worker* w)
{
 w->next = m_head.next;
 m_head.next = w;

}
//Press to insert objectint insert(Worker* w)
{
 Worker* cur = m_head.next; // Current node Worker* pre = &m_head; // Previous node previously while (cur)
 {
 if (w->id < cur->id) // Find this location break;

 pre = cur;
 cur = cur->next; // Find the last object }

 // Insert behind the pre node w->next = pre->next;
 pre->next = w;
 return 0;
}
//Delete the objectint remove(int id)
{
 Worker* cur = m_head.next;//The current node is the first object Worker* pre = &m_head;//The previous node of the current node is the head node, pointing to the first object while (cur)
 {
 if (id == cur->id)//Find the node to be deleted {
 pre->next = cur->next;
 free(cur);//Delete this node return 1;//Return 1 after successful deletion }
 pre = cur;
 cur = cur->next;

 }
 return 0;
}
//Find the objectint find(int id)
{
 Worker* p = m_head.next;
 while (p)
 {
 if (id == p->id)
 {
 printf("ID:%d\nName:%s\nSex:%s\nAge:%d\nEdu-exp:%s\nWage:%d\nAdress:%s\nPhone:%s\n",
 p->id, p->name, p->sex, p->age, p->edu_exp, p->wage, p->adress, p->phong);
 return 1;//Return 1 after finding the target }
 p = p->next;
 }
 return 0;
}

//Travelvoid show_all()
{
 Worker* p = m_head.next;
 if (!p)
 {
 printf("No employee information yet!");
 return;
 }
 printf("Work number, name, gender, age, education, salary, residence address, telephone number\n");
 printf("----------------------------------------------------------------\n");
 while (p)
 {

 printf("%d %s %s %d %s %d %s %s\n", p->id, p->name, p->sex, p->age, p->edu_exp,
 p->wage, p->adress, p->phong);
 p = p->next;
 }
}
//Save data to the fileint save()
{
 const char* filename = "F:\\";
 FILE* fp = fopen(filename, "a");
 if (fp == NULL)
 {
 printf("can not open the file....");
 exit(0);
 }
 Worker* p = m_head.next;
 while (p)
 {
 fprintf(fp, "\r");
 fprintf(fp, "%d ", p->id);
 fprintf(fp, "%s ", p->name);
 fprintf(fp, "%s ", p->sex);
 fprintf(fp, "%d ", p->age);
 fprintf(fp, "%s ", p->edu_exp);
 fprintf(fp, "%d ", p->wage);
 fprintf(fp, "%s ", p->adress);
 fprintf(fp, "%s ", p->phong);
 fprintf(fp, "\t\r\n");
 p = p->next;

 }


 fclose(fp);
 return 0;

}

//Modify the objectvoid rewrite(int id)
{
 Worker* p = m_head.next;
 while (p)
 {
 if (id == p->id)
 {
 user_input(p);
 }
 p = p->next;
 }

}
// Main menuvoid List()
{
 Worker* w = NULL;
 char key;
 while (1)
 {

 do
 {
 system("cls");
 printf("*******************************************************\n");
 printf("* Main menu operation interface *\n");
 printf("*    *\n");
 printf("* 1. Enter employee information *\n");
 printf("* 2. Browse employee information *\n");
 printf("* 3. Query employee information *\n");
 printf("* 4. Delete employee information *\n");
 printf("* 5. Modify employee information *\n");
 printf("* 6. Instructions for use *\n");
 printf("* 7. Exit *\n");
 printf("*    *\n");
 printf("*******************************************************\n");

 key = getchar();

 } while (key != '1'&&key != '2'&&key != '3'&&key != '4'
 &&key != '5'&&key != '6'&&key != '7');

 switch (key)
 {
 case '1':system("cls");
 while (1)
 {
 Worker* w = (Worker*)malloc(sizeof(Worker));
 user_input(w);
 insert(w);
 if (getchar() == 'N')
 {
  break;
 }
 }
 save();
 free(w);
 break;
 case '2':system("cls");
 show_all();
 system("pause");
 break;
 case '3':system("cls");
 if (!m_head.next)
 {
 printf("No employee information yet!");
 system("pause");
 break;
 }
 while (1)
 {
 int n;
 printf("---------------------------------\n");
 printf("Please enter the ID number you want to find:");
 scanf("%d", &n);
 if (!find(n))
 {
  printf("The employee information with ID number %d cannot be found...\n", n);
 }
 char ch = getchar();
 if (ch == 'N')
 {
  break;
 }

 }
 break;

 case '4':system("cls");
 if (!m_head.next)
 {
 printf("No employee information yet!");
 system("pause");
 break;
 }
 while (1)
 {
 int n;
 printf("---------------------------------\n");
 printf("Please enter the ID number to be deleted:");
 scanf("%d", &n);
 if (remove(n))
 {
  printf("Successfully deleted employee information with ID number %d.\n", n);
 }
 else
  printf("Cannot delete employee information with ID number %d.\n", n);
 char ch = getchar();
 if (ch == 'N')//Press N to exit {
  break;
 }
 }
 break;
 case '5':system("cls");//
 if (!m_head.next)
 {
 printf("No employee information yet!");
 system("pause");
 break;
 }
 while (1)
 {
 int n;
 printf("Please enter the ID number to be modified:\n");
 scanf("%d", &n);
 printf("Please modify:\n");
 rewrite(n);
 if (getchar() == 'N')
 {
  break;
 }
 }
 break;
 case '6':system("cls");
 printf("Instructions for use of the employee system: Press the corresponding number to enter the corresponding submenu. If you want to exit, press N\n to start without data, you need to enter first.\n");
 system("pause");
 break;
 case '7':system("cls");//
 return;
 break;

 }
 }
}
int main()
{

 List();
 return 0;
}