# include 
#include 
# define N 30 
Typedef struct student 
{
Long id; 
Char name [20]. 
Int score [4]; 
} STUDENT; 
Void the write (STUDENT stu [], int num, int x); 
Void the read (STUDENT s [], int num); 
Void print (STUDENT s [], int num); 
Void px (STUDENT s [], int num); 
Void copy (STUDENT s [], int num); 
Int main () 
{
STUDENT s [N]. 
Int n, num=5; 
Printf (" 1: create student information file and output; \ n2: sort by student number and output; \ n3: sort by name and output; Increases the \ n4 interchange student information; Data \ n5: to delete a student; \n"); 
Do {
The scanf (" % d ", & amp; n); 
The switch (n) 
{
Case 1: 
Read (s, num); 
Print (s, num); 
break; 
Case 2: 
Px (s, num); 
Print (s, num); 
break; 
} 
} while (n!=6); 
return 0; 
} 
Void the write (STUDENT stu [], int num, int x) 
{
The FILE * fp. 
Int I, j; 
If (x=1) 
{
If ((fp=fopen (" E: \ \ c language homework winter vacation \ \ student data ", "w"))==NULL) 
{
Printf (" error \ n "); 
exit(0); 
} 
} 
The else 
{
If ((fp=fopen (" E: \ \ c language homework winter vacation \ \ sno data ", "w"))==NULL) 
{
Printf (" error \ n "); 
exit(0); 
} 
} 
for(i=0; i{
Fprintf (fp, "% 010 ld % 8 s," stu [I] id, stu [I] name); 
for(j=0; j<4. J++) 
{
Fprintf (fp, "% 4 d," stu [I] score [j]); 
} 
Fprintf (fp, "\ n"); 
} 
The fclose (fp); 
} 
Void the read (STUDENT s [], int num) 
{
The FILE * fp. 
int i,j; 
If ((fp=fopen (" E: \ \ c language homework winter vacation \ \ student data ", "r"))==NULL) 
{
Printf (" error \ n "); 
exit(0); 
} 
for(i=0; i{
The fscanf (fp, "% ld", & amp; S [I]. Id); 
Fscanf (fp, "% s", s [I] name); 
for(j=0; j<4. J++) 
{
The fscanf (fp, "% d", & amp; S [I] score [j]); 
} 
} 
The fclose (fp); 
} 
Void print (STUDENT s [], int num) 
{
int i,j; 
Printf (" student id \ \ t t \ \ t t name mathematics language English \ t \ n \ t grade "); 
for(i=0; i{
Printf (" % 010 10 ld % s ", s [I] id, s [I] name); 
for(j=0; j<4. J++) 
{
Printf (" % d ", s [I] score [j]); 
} 
printf("\n"); 
} 
} 
Void px (STUDENT s [], int num) 
{
int i,j,k; 
The STUDENT team; 
for(i=0; i{
K=I; 
For (j=I + 1; j{
If (s [k]. Id> S [j]. Id) 
{
K=j; 
} 
} 
If (k!=I) 
{
The team [I]=s; 
S [j] [I]=s; 
S [j]=team; 
} 
} 
Write (s, num, 2); 
}