STACK OPERATIONS USING LINKED LIST

#include<stdio.h>

#include <stdlib.h>

typedef struct node

{

    int data;

    struct node *link;

}NODE;

void Push(int);

int  pop();

void Display();

NODE *top=NULL;   /* Global Declarations */

main()

{

   int opn,elem;

    do

    {

        clrscr();

        printf("\n ### Linked List Implementation of STACK Operations ### \n\n");

        printf("\n Press 1-Push, 2-Pop, 3-Display,4-Exit\n");

        printf("\n Your option ? ");

        scanf("%d",&opn);

        switch(opn)

        {

        case 1:

            printf("\n\nRead the Element tobe pushed ?");

            scanf("%d",&elem);

            Push(elem);

            break;

        case 2:

            elem=Pop();

            if(elem != -1)

                printf(" Deleted Node(From Top)with the Data: %d\n",elem);

            break;

        case 3: printf("Linked List Implementation of Stack: Status:\n");

            Display(); break;

        case 4: printf("\n\n Terminating \n\n"); break;

        default: printf("\n\nInvalid Option !!! Try Again !! \n\n");

            break;

        }

        printf("\n\n\n\n  Press a Key to Continue . . . ");

        getch();

    }

while(opn != 4);

}

void Push(int info){

    NODE *temp;

    temp=(NODE *)malloc(sizeof(NODE));

    if( temp == NULL)

        printf(" Out of Memory !! Overflow !!!");

    else    {

        temp->data=info;

        temp->link=top;

        top=temp;

        printf(" Node has been inserted at Top(Front) Successfully !!");

    }

}

int Pop()

{

    int info;

    NODE *t;

    if( top ==  NULL) { printf(" Underflow!!!"); return -1; }

    else    {

        t=top;

        info=top->data;

        top=top->link;

        t->link=NULL;

        free(t);

        return(info);

    }}

void Display()

{

    NODE *t;

    if( top == NULL) printf("Empty Stack\n");

    else    {

        t=top;

        printf("Top->");

        while(t)

        {

            printf("[%d]->",t->data);

            t=t->link;

        }

        printf("Null\n");

    }

}

Output:

### Linked List Implementation of STACK Operations ###

 Press 1-Push, 2-Pop, 3-Display,4-Exit

 Your option ? 1

Read the Element tobe pushed ?2

 Node has been inserted at Top(Front) Successfully !!

  Press a Key to Continue . . .

 Press 1-Push, 2-Pop, 3-Display,4-Exit

 Your option ?

1

Read the Element tobe pushed ?4

 Node has been inserted at Top(Front) Successfully !!

  Press a Key to Continue . . .

 Press 1-Push, 2-Pop, 3-Display,4-Exit

 Your option ? 3

Linked List Implementation of Stack: Status:

Top->[4]->[2]->Null

  Press a Key to Continue . . .

 Press 1-Push, 2-Pop, 3-Display,4-Exit

 Your option ? 2

 Deleted Node(From Top)with the Data: 4

  Press a Key to Continue . . .

 Press 1-Push, 2-Pop, 3-Display,4-Exit

 Your option ? 3

Linked List Implementation of Stack: Status:

Top->[2]->Null