Structures and arrays in C - c

Question

I must create a program focusing on the use of structures.
The program will ask the user to enter the number of students for whom he will later add specific information (name, surname, average grade).
For some reason, when I start the the program, I enter the number of students i want, after that I enter the info of the first student and then the program terminates.
Here's what I've tried.
#include <stdio.h>
#include <stdlib.h>
struct student
{
char *name;
char *surname;
float *average;
};
void inputs(struct student *a, int size);
int main()
{
int size;
printf("Enter the number of students: ");
scanf("%d", &size);
struct student *data;
data = (struct student *)malloc(size*sizeof(struct student));
if(data==NULL) {
printf("Cannot allocate memory. The program will now terminate.");
return -1;
}
inputs (data, size);
return 0;
}
void inputs(struct student *a, int size)
{
int j=0;
int i;
for(i=0; i<size; i++) {
printf("Enter the name of the student number %d: ", j+1);
scanf("%s", a->name);
printf("Enter the surname of the student number %d: ", j+1);
scanf("%s", a->surname);
printf("Enter the average grade of the student number %d: ", j+1);
scanf("%f", a->average);
j++;
a++;
}
}

Answer 1

This code works:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
struct student
{
char name[30];
char surname[30];
float average;
};
void inputs(struct student *a, int size);
int main()
{
int size;
int i=0; // we need i
char string[100];
printf("Enter the number of students: ");
// scanf can be tricky lets use fgets
fgets( string , 99 , stdin );
size= atoi(string);
struct student **data; // array of struct
// get memory for the pointers to pointer
data=(struct student **) calloc( size , sizeof(char *));
// now each struct need space
for( i=0 ; i<size ; i++)
{
data[i] = malloc(sizeof(struct student));
if(data[i]==NULL) {
printf("Cannot allocate memory. The program will now terminate.");
return -1;
}// end if
}// end for loop
// input each student
for( i=0 ; i<size ; i++)
inputs (data[i], i );
return 0;
}
void inputs(struct student *a, int num)
{
int j=0;
char string[100];
// scanf can be tricky lets use fgets
printf("Enter the name of the student number %d: ", num+1);
fgets(a->name, 29, stdin);
printf("Enter the surname of the student number %d: ", num+1);
fgets( a->surname , 29, stdin);
printf("Enter the average grade of the student number %d: ", num+1);
fgets( string , 99, stdin);
a->average=atof(string);
}