# include & ltstdlib.h & gt
# include & ltstring.h & gt
Structural stud
{
Long num
char name[20]；
Double integral;
};
Typedef structure stucode
{
Structural research students;
struct stucode * next
} L；
void menu()；
void create list(struct stu code * * r)；
void out(struct stu code * r)；
void search 1(struct stu code * r)；
void search 2(struct stu code * r)；
void del(struct stu code * * r)；
void insert(struct stu code * * r)；
void sort(struct stu code * * r)；
void main()
{
Char selection;
int flag = 1；
struct stucode * r = NULL
While (sign)
{
System ("CLS");
menu()；
choose = getchar()；
Switch (select)
{
Case "1":
Create a list (& ampr);
out(r)；
Printf ("Test function1\ nPress any key to continue \ n");
getchar()；
getchar()；
Break;
Case "2":
search 1(r)；
Printf ("Test function1\ nPress any key to continue \ n");
getchar()；
getchar()；
Break;
Case "3":
Search 2 (r);
Printf ("Test function1\ nPress any key to continue \ n");
getchar()；
getchar()；
Break;
Case "4":
Del (& Ampr);
out(r)；
Printf ("Test function1\ nPress any key to continue \ n");
getchar()；
getchar()；
Break;
Case "5":
Insert (& ampr)；;
out(r)；
Printf ("Test function1\ nPress any key to continue \ n");
getchar()；
getchar()；
Break;
Case "6":
Sorting (& AMPR);
out(r)；
Printf ("Test function1\ nPress any key to continue \ n");
getchar()；
getchar()；
Break;
Case "7":
out(r)；
Printf ("Test function 7 \ nPress any key to continue \ n");
getchar()；
getchar()；
Break;
Case "0":
flag = 0；
printf("The end。 \ n ")；
Break;
Default value: printf ("\ nWrong selection! (Wrong selection, please re-select! )\ n”)； getchar()； getchar()；
}
}
}
void create list(struct stu code * * r)
{
struct stucode *p，* t；
Dragon n;
char a[20]；
Double s;
if(* r)* r = NULL；
Printf(" \n n nPlease enter: \ n Student ID (please arrange in ascending order) name score (please enter three zeros to end) \ n ");
Scanf("%ld%s%lf ",¬ applicable. s)；
If(n==0) returns;
p =(L *)malloc(sizeof(L))；
p->； student . num = n；
strcpy(p-& gt； student.name，a)；
p->； student . score = s；
p->； next = NULL
* r = p；
Scanf("%ld%s%lf ",¬ applicable. s)；
When (noun)
{
t = p；
p =(L *)malloc(sizeof(L))；
p->； student . num = n；
strcpy(p-& gt； student.name，a)；
p->； student . score = s；
p->； next = NULL
t->； next = p；
Scanf("%ld%s%lf ",¬ applicable. s)；
}
}
void search 1(struct stu code * r)
{
Long x;
If (! r)
{
Printf ("There is no student information to query! \ n ")；
Return;
}
Printf ("Please enter the student number of the student information to be queried: \ n");
scanf("%ld "，& ampx)；
And (r& & amp->; Student. num! =x)
r = r-& gt； Next;
if(r==NULL)
Printf ("Error! There are no such students! \ n ")；
other
printf("%ld %s %.2lf\n "，r-& gt； Student.num, r- > student name, r-> student . score)；
}
void search2(struct stucode *r)
{
char m[20]；
If (! r)
{
Printf ("There is no student information to query! \ n ")；
Return;
}
Printf ("Please enter the student name of the student information to be queried: \ n");
scanf("%s "，m)；
And (r & strcmp (r->; Student name, m))
r = r-& gt； Next;
if(r==NULL)
Printf ("Error! There are no such students! \ n ")；
other
printf("%ld %s %.2lf\n "，r-& gt； Student.num, r- > student name, r-> student . score)；
}
void del(struct stucode **r)
{
Long k;
struct stucode *p=*r，* t；
If (! (*r))
{
Printf ("There is no student information to delete! \ n ")；
Return;
}
Printf ("Please enter the student ID of the student information to be deleted: \ n");
scanf("%ld "，& ampk)；
If (p->; Number of students ==k)
* r =(* r)-& gt； Next, free (P);
other
{
while(p->； next & amp& ampp->； Next-> Student. num! =k)
p = p-& gt； Next;
If (p->; next==NULL)
Printf ("Error! There are no such students! \ n ")；
other
{
t = p-& gt； Next;
p->； next = p-& gt； Next-> Next;
Free (t);
}
}
}
Null insertion (structure stucode **r)
{
Dragon n;
char a[20]；
Double s;
L *p，*t，* k；
Printf ("Please enter the student number name score of the student information to be inserted: \ n");
Scanf("%ld%s%lf ",¬ applicable. s)；
p =(L *)malloc(sizeof(L))；
p->； student . num = n；
p->； student . score = s；
strcpy(p-& gt； student.name，a)；
If (! (*r))
{
* r = p；
(* r)-& gt； next = NULL
Return;
}
If (p->; Student number & lt (* r)-> Number of students)
p->； next=(*r)，(* r)= p；
other
{
t = * r；
k = t；
while(t->； next & amp& ampt->； Next-> Student number & lt = p->; Number of students)
t = t-& gt； Next;
p->； next = t-& gt； Next;
t->； next = p；
* r = k；
}
}
Void sort (struct stucode **r)
{
struct stucode *t，*p，*q，* z；
If (! r)
{
Printf ("There is no student information to sort! \ n ")；
Return;
}
If (! (*r)||！ (* r)-& gt； Next)
Return;
t = * r；
p = t-& gt； Next;
t->； next = NULL
while(p)
{
q = p->； Next;
If (p->; Students. Score & gtt->; student.score)
{
p->； next = t；
t = p；
}
other
{
z = t；
while(z->； next & amp& ampz-& gt； Next-> Student. Score & gt = p->; student.score)
z = z-& gt； Next;
p->； next = z-& gt； Next;
z-& gt； next = p；
}
p = q；
}
* r = t；
}
void out(struct stucode *r)
{
printf(" \ n \ n ")；
If (! r)
{
Printf ("There is no student information to output! \ n ")；
Return;
}
while(r)
{
printf("%ld %s %.2lf\n "，r-& gt； Student.num, r- > student name, r-> student . score)；
r = r-& gt； Next;
}
printf(" \ n \ n ")；
}
Invalid menu ()
{
Printf("\n Student Information Management System \ n ");
Printf ("\ nmenu \ n \ n");
Printf("\n 1 Create a linked list and display it \ n ");
Printf("\n 2 Find the student information of a student number \ n ");
Printf("\n 3 Find student information of a certain name \ n ");
Printf("\n 4 Delete the student information of a student number \ n ");
Printf("\n 5 Insert new student information \ n ");
Printf("\n 6 output in descending order of fractions \ n ");
printf(" \ n 7 output \ n ")；
printf(" \ n exit \ n ")；
Printf ("\ nPlease select an option to execute: \ n");
}