Stack implementation with the help of linked list in C

Stack implementation can be done in three ways
1> using arrays
2> using linked lists
3> using 2 queues


let's see the program for stack implementation with the help of linked list


#include<stdio.h>
struct node1{
    int top, size;
    int *sptr;

};
typedef struct node1 stack;
void push(stack *s,int value )
{
    if(s->top!=s->size-1)
    {
        s->top ++;
        s->sptr[s->top] = value;
    }
    else
    {
        printf("stack is already full so can't enter %d \n",value);
    }

}
int  pop(stack *s)
{
   if (isempty(s))
   {
       printf("stack is already empty ");
        return 0;
   }
   else
    {
        int x= s->sptr[s->top];
        s->top = s->top -1 ;
        return x;
    }
}
int isempty(stack *s)
{
    if(s->top==-1)
    {
        return 1;
    }
    else
        return 0;
}
void print(stack s1)
{
    int i ;
    for ( i=0;i<=(s1.top);i++)
    {
       printf("%d\n",s1.sptr[i]) ;
    }

}
void main()
{
    stack s1;
    printf("enter the size of stack");
    scanf("%d",&s1.size);
    s1.sptr=(int*)malloc(sizeof(int)*(s1.size));
    s1.top=-1;
    int m=pop(&s1);
    printf("%dabc\n",m);
    push(&s1,8);
    push(&s1,23);
    push(&s1,43);
    push(&s1,21);
    push(&s1,54);
    print(s1);
    m=pop(&s1);

    printf("the value after pop is %d",m);

}