Стек на основе односвязного списка

typedef struct GRAD {
                 int numb, year, numgrad, rec;
                 struct GRAD *next;
                } GRAD; 
void push(GRAD **head, int numb1, int year1, int numgrad1, int rec1);
void pop(GRAD **head);
void view(GRAD **head);

#include <stdio.h>
#include <stdlib.h>
#include "stack.h"
void push(GRAD **head, int numb1, int year1, int numgrad1, int rec1)
{
    GRAD *t= (GRAD *)malloc(sizeof (GRAD));
    t->numb=numb1;
    t->numgrad=numgrad1;
    t->rec=rec1;
    t->year=year1;
    t->next= (*head);
    (*head)=t;
}
void pop(GRAD **head)
{
     GRAD *prev=NULL;
     int numb1, year1, numgrad1, rec1;
    if (head!=NULL)
    {
        prev=(*head);
        numb1=prev->numb;
        year1=prev->year;
        numgrad1=prev->numgrad;
        rec1=prev->rec;
        printf ("\n\n\n\nThe deleted element of the stack is:\nThe number of the school: %d\nThe number of release year: %d\nThe number of graduates: %d\nThe number of new entrants to higher education: %d\n", numb1, year1, numgrad1, rec1);
        (*head)=(*head)->next;
     }
     else
     printf ("The stack is empty!");
     free(prev);
 }
void view(GRAD **head)
{
    GRAD *q;
    if (head!=NULL)
    {
    for (q=head; q!=NULL; q=(*q).next)
          printf ("The number of the school: %d\nThe number of release year: %d\nThe number of graduates: %d\nThe number of new entrants to higher education: %d\n\n\n\n\n\n", (*q).numb, (*q).year, (*q).numgrad, (*q).rec);
    }
    else
    printf ("The stack is empty!\n");
    free(q);
}

#include <stdio.h>
#include <stdlib.h>
#include "stack.h"
int main (int argc, char* argv[])
{
    int x=0, c=0, numb1=0, year1=0, numgrad1=0, rec1=0;
    GRAD *head=NULL;
    do{ 
       printf ("Menu:\n1. Push. Add items.\n2. Pop. Retrieving items.\n3. View. View the stack.\n"); 
       printf ("Choose what interests you\n"); 
       scanf ("%d", &x); 
       switch (x) 
        { 
          case 1: {
                    printf ("Enter information about the graduates:\n"); 
                    printf ("Enter the number of the school:\n"); 
                    scanf ("%d", &numb1); 
                    printf ("Enter the number of release year:\n"); 
                    scanf ("%d", &year1); 
                    printf ("Enter the number of graduates:\n"); 
                    scanf ("%d", &numgrad1); 
                    printf ("Enter the number of new entrants to higher education:\n"); 
                    scanf ("%d", &rec1);
                    push(head, numb1, year1, numgrad1, rec1);
                    break;
          }
          case 2: pop(head); break; 
          case 3: view(head); break; 
          default: printf ("Error! Enter another number\n"); 
         } 
       printf ("To continue? Yes=1, No=2\n"); 
       scanf ("%d", &c); 
      } 
   while (c==1); 
   system("PAUSE"); 
   return 0; 
}

push(&head,...);
pop(&head);
view(&head);

void view(GRAD **head)
{
...
    for (q=&head; q!=NULL; q=(*q).next)
...
    // free(q); - убрать
}