1. /*
Linked List Implementation of the Stack in C
Author: Kasun Ranga Wijeweera
Email: krw19870829@gmail.com
Date: 20130501
*/
#include<stdio.h>
#include<conio.h>
#include<alloc.h>
typedef struct stackNode *link;
struct stackNode
{
int data;
link next;
};
typedef struct
{
link top;
}stack;
void initStack(stack *s)

2. {
s->top=NULL;
}
int isEmpty(stack *s)
{
if((s->top)==NULL)
{
return 0;
}
else
{
return 1;
}
}
void pushStack(stack *s,int x)
{
link t=(link)malloc(sizeof(struct stackNode));
t->data=x;
t->next=s->top;
s->top=t;
}
int popStack(stack *s)

3. {
link t;
int x;
t=s->top;
x=t->data;
s->top=t->next;
free(t);
return x;
}
void printStack(stack *s)
{
link t=s->top;
while(t!=NULL)
{
printf("%d ",t->data);
t=t->next;
}
}
void main()
{
int x;
stack *s;

4. clrscr();
s=(stack*)malloc(sizeof(stack));
initStack(s);
pushStack(s,10);
pushStack(s,20);
if(isEmpty(s))
x=popStack(s);
pushStack(s,30);
pushStack(s,40);
pushStack(s,50);
if(isEmpty(s))
x=popStack(s);
printStack(s);
free(s);
getch();
}