Stack implementation using Linked List through C Linux Code

/* stack using linked list */

#include<stdio.h>

#include<stdlib.h>

struct node

{

int data;

struct node *next;

};

void push(int);

void display();

int pop();

struct node *top=NULL;

int main()

{

push(10);

push(20);

push(30);

display();

pop();

display();

pop();

display();

pop();

display();

return 0;

}

void push(int d)

{

struct node *newnode;

newnode=(struct node *)malloc(sizeof(struct node));

if(newnode==NULL) printf("\nout of memory\n");

else

{

newnode->data=d;

newnode->next=top;

top=newnode;

}

}

int pop()

{

struct node *temp;

temp=(struct node *)malloc(sizeof(struct node));

if(top==NULL)

{

printf("Under flow\n");

return -1;

}

else

{

temp=top;

//int info;

//info=top->data;

top=top->next;

if(temp!=NULL)

free(temp);

//return(info);

}

}

void display()

{

printf("\ndisplay callled:\n");

struct node *current;

if(top==NULL)

printf("\nstack empty\n");

else

{

current=top;

while(current)

{

printf("%d ",current->data);

current=current->next;

}

}

printf("\n");

}

/*

display callled:

30 20 10

display callled:

20 10

display callled:

10

display callled:

stack empty

*/