Let's take a look at how to change the warning of this program.

Let's take a look at how to change the warning of this program-Linux general technology-Linux programming and kernel information. The following is a detailed description. Main. c
# Include
# Include
# Include "lianbiao. h"
/* # Include
# Define maxname 100
# Define stu struct student
Typedef struct {
Char name [maxname];
Int num;
Int math;
Int chinese;
Stu * next;
} Student ;*/
Int main ()
{
Student * head;
Student * pl;
Head = (student *) malloc (sizeof (student ));
Int a, number, c;
C = 0;
Printf ("now creat a student 'date \ n ");
Printf ("% d", c );
Head = creat ();
While (c = 0 ){
Printf ("what do you want to do? \ N ");
Printf ("please input 0 (exit), 1 (del a student), 2 (add student), 3 (find a student), 4 (display) \ n ");
Scanf ("% d", & );
Switch (){
Case 0: c = 1; break;
Case 1: printf ("please input the student's number: \ n ");
Scanf ("% d", & number );
Head = del (number, head); break;
Case 2: printf ("now start to add: \ n ");
Head = add (head); break;
Case 3: printf ("please input the student's number: \ n ");
Scanf ("% d", & number );
Pl = find (number, head); break;
Case 4: head = display (head); break;
Default: c = 1; break;
}

}

}
Lianbiao. h
// # Define stu struct student
# Define maxname 100
Typedef struct {
Char name [maxname];
Int num;
Int math;
Int chinese;
Struct student * next;
} Student;
Student * creat (void );
Student * del (int number, student * p );
Student * add (student * p );
Student * find (int number, student * p );
Student * display (student * p );
Lianbiao. c
# Include
# Include
# Include
# Include "lianbiao. h"
Student * creat (void ){
Student * p1;
Student * p2;
Student * p;
P1 = (student *) malloc (sizeof (student ));
P1-> next = NULL;
P2 = p1;
While (1 ){
P = (student *) malloc (sizeof (student ));
Printf ("please input student's number from small to large \ n ");
Scanf ("% d", & p-> num );
If (p-> num = 0) break;
Printf ("please input student's name \ n ");
Scanf ("% s", & p-> name );
Printf ("please input student's math number \ n ");
Scanf ("% d", & p-> math );
Printf ("please input student's chinese number \ n ");
Scanf ("% d", & p-> chinese );
If (p2-> next = NULL ){
P1-> next = p; p-> next = NULL; p1 = p; printf ("chenggong \ n ");}
Else {p1-> next = p; p-> next = NULL; p1 = p; printf ("chenggong \ n ");}
} Return (p2 );
}

Student * del (int number, student * p ){
Student * p1;
Student * p2;
P1 = p2 = p;
If (p-> next = NULL) printf ("eror: this lianbiao is null! ");
// If (p-> num = number) p2 = p-> next;
If (p-> num = number) p2 = p-> next;
Else p = p-> next;
While (p-> num! = Number & p-> next! = NULL ){
P1 = p; p = p-> next;
}
If (p-> next = NULL) printf ("eror: there is no this student! ");
P1-> next = p-> next;
Free (p );
Return (p2 );
}

Student * add (student * p ){
Int number;
Student * p1;
Student * p2;
Student * p3;
If (p-> next = NULL) printf ("eror: this lianbiao is null! ");
P2 = p;
P = p-> next;
Printf ("please input student's number \ n ");
Scanf ("% d", & number );
While (p-> num <number & p-> next! = NULL ){
P = p-> next;
} Printf ("chenggong \ n ");
If (p-> num = number) {printf ("eror: this student is cunzai! "); Return (p2 );}
P3 = (student *) malloc (sizeof (student ));
P3-> num = number;
Printf ("please input student's name \ n ");
Scanf ("% s", & p3-> name );
Printf ("please input student's math number \ n ");
Scanf ("% d", & p3-> math );
Printf ("please input student's chinese number \ n ");
Scanf ("% d", & p3-> chinese );
If (p-> next = NULL) {p-> next = p3; p3-> next = NULL; p = p3 ;}
Else {p3-> next = p;
P1-> next = p3 ;}
Return (p2 );
}
Student * find (int number, student * p ){
Int I = 0;
If (p-> next = NULL) printf ("eror: this lianbiao is null! ");
While (p-> num! = Number & p-> next! = NULL ){
P = p-> next; I ++;
}
If (p-> next = NULL)
If (p-> num! = Number)
Printf ("eror: this student is not egzist! ");
Printf ("chenggong \ n ");
Printf ("% d", I );
Printf ("% d, % d, % s, % d \ n", p-> num, p-> math, p-> name, p-> chinese );
Return (p );
}
Student * display (student * p)
{
Student * p1;
Student * p2;
P2 = p;
P1 = p-> next;
While (p1-> next! = NULL ){
Printf ("% d, % s, % d, % d \ n", p1-> num, p1-> name, p1-> math, p1-> chinese );
P = p1; p1 = p1-> next;
}
Printf ("% d, % s, % d, % d \ n", p1-> num, p1-> name, p1-> math, p1-> chinese );
Return (p2 );
}
The following warning is prompted when lianbiao. o is generated:
Lianbiao. c: In the 'creat' function:
Lianbiao. c: 24: Warning: incompatible pointer type assignment
Lianbiao. c: 25: Warning: Assignment of incompatible pointer types
Lianbiao. c: In the 'del 'function:
Lianbiao. c: 35: Warning: incompatible pointer type assignment
Lianbiao. c: 36: Warning: incompatible pointer type assignment
Lianbiao. c: 38: Warning: incompatible pointer type assignment
Lianbiao. c: In the 'add' function:
Lianbiao. c: 53: Warning: incompatible pointer type assignment
Lianbiao. c: 57: Warning: Assignment of incompatible pointer types
Lianbiao. c: 68: Warning: incompatible pointer type assignment
Lianbiao. c: 69: Warning: incompatible pointer type assignment
Lianbiao. c: 70: Warning: incompatible pointer type assignment
Lianbiao. c: In the 'Find 'function:
Lianbiao. c: 77: Warning: Assignment of incompatible pointer types
Lianbiao. c: In the 'display' function:
Lianbiao. c: 92: Warning: incompatible pointer type assignment
Lianbiao. c: 95: Warning: Assignment of incompatible pointer types