This program maintains a linked list of students, where each student contains a name (one-word only) and a GPA. The program operates as follows: Prompts the user for names and GPAs, building the list with calls to add, printing the list after each add
Prompts the user for a name, and then prints the GPA of that student (-1 if the name is not in the list)
You must complete the following:
Write the function getGPA that returns the gpa of the name passed to it, or -1.0 if the name doesn’t exist.
Re-write add so that all the students will be ordered by descending GPA. For those with the same GPA, they will be ordered ascending alphabetically.
Do not add a name if it already exists in the list and print the error message: "Student named %s exists.\n"
It is recommended to write a helper function compareStudents that compares two students and returns -1, 1 or 0, depending on the positions of the two students in the sorted linked list.
Two sample inputs for the program are shown below:
Fred 3.5
Barney 2.4
Betty 3.9
Wilma 3.5
xxx 0
Fred
Betty
xxx
Betty 3.5
Fred 2.5
Fred 2.9
Wilma 2.9
Wilma 3.0
xxx 0
Pebbles
xxx
Code :

#include

#include

#include

typedef struct _student {

char *name;

double gpa;

struct _student *next;
} Student;
Student *createStudent(char name[], double gpa, Student *next) {
Student *pNew = malloc(sizeof(Student));
pNew->name = malloc(strlen(name) + 1);
strcpy(pNew->name, name);
pNew->gpa = gpa;
pNew->next = next;
return pNew;
}
int compareStudents(Student *pNew, Student *pExisting) {
//code here
return -1;
}
Student *add(Student *head, char name[], double gpa) {
//code here
return createStudent(name, gpa, head);
}
void print(char prefix[], Student *head) {
printf("%s", prefix);
for (Student *ptr = head; ptr != NULL; ptr = ptr->next)
printf("[%s-%g] ", ptr->name, ptr->gpa);
printf("\n");
}
double getGPA(Student *head, char name[]) {
//code here
return -1.0;
}
int main(void) {
char name[100];
double gpa;
Student *head = NULL;
while (1) { // build the list
printf("\nEnter a name (one word) and gpa, or xxx and 0 to exit: ");
scanf("%s%lf", name, &gpa);
if (strcmp(name, "xxx") == 0) break;
head = add(head, name, gpa);
print("\n\tNow the list is: ", head);
}
while (1) { // perform search
printf("\nEnter a name to look up the gpa or xxx to exit: ");
scanf("%s", name);
if (strcmp(name, "xxx") == 0) break;
gpa = getGPA(head, name);
if (gpa < 0)
printf("\n\t%s does not exist\n", name);
else
printf("\n\t%s has a GPA of %g\n", name, gpa);
}
return 0;
}