Stack

stc.c

#include<stdio.h>
#include<stdlib.h>

struct stack      
{
	int info;
	struct stack *next;
};
typedef struct stack *s;

void push(s *sptr ,int p)
{
	
	s s2;
	s2=(s)malloc(sizeof(struct stack));
	if(s2==NULL)
	{
		printf("no memory");
		exit(1);
	}

	else
	{
		s2->info=p;
		s2->next=*sptr;
		*sptr=s2;
	}
}

int pop(s *sptr)
{
	s s2=*sptr; //Why???
	int px;
	if(*sptr == NULL)
	{
		printf("stack is empty");
		return;
	}
	else
	{
		px = (*sptr) -> info;
        *sptr = (*sptr) -> next;
        //free(sptr);
        return px;
	}
}

void disp(s *sptr)
{
    s temp=*sptr;	
	printf("the elements in stack are:\n");
    while(temp->next!=NULL)
	{
	    printf("%d\n",(temp)->info);
	    (temp)=(temp)->next;
	}
	printf("%d\n",temp -> info);
	
}


void main()
{
	int c,i;
    s s1=NULL;
   
   do{
	   printf("enter operation:-");
	   scanf("%d",&c);
	   switch(c)
	   {
	   case 1:  printf("enter data:-");
	             scanf("%d",&i);
	             push(&s1,i);
				 break;
			   
	   case 2:pop(&s1);break;
       case 3:disp(&s1);  break;
	   }
   }while(s1!=NULL);
}

Fixed and working