Stack

#include<stdio.h>
#include<stdlib.h>
//#include"stack.h"

struct node{
    int data;
    struct node *next;
};

struct list{
    struct node *head;
};

struct node* createNode()
{
   int a;
   struct node* x=malloc(sizeof(struct node));
   scanf("%d",&a);
   x->data=a;
   x->next=NULL;
   return x;
}
int push(struct list* l,struct node* newnode)
{
    if(l->head==NULL)
    {
        l->head=newnode;
    }
    else
    {
        newnode->next=l->head;
        l->head=newnode;
    }
}
void displayList(struct list* l)
{
    struct node* x = l->head;
    while(x!=NULL)
    {
        printf("\n %d \n",x->data);
        x = x->next;
    }
    getch();
}
struct node* pop(struct list* l)
{
    struct node* x;
    if(l->head==NULL)
    {
        return 0;
    }
    else
    {
        x=l->head;
        l->head=(l->head)->next;
    }
    return x;
}

int getChoice(int choice){
    char ch=10;
    while(ch!=13){
        system("cls");
        if(choice==1){
            printf("\n   -->\tP U S H");
        }
        else printf("\n\tPush");
        if(choice == 2)
            printf("\n   -->\tP O P");
        else printf("\n\tPop");
        if(choice == 3)
            printf("\n   -->\tD I S P L A Y");
        else printf("\n\tDisplay");
        if(choice == 4)
            printf("\n   -->\tQ U I T");
        else printf("\n\tQuit");
        printf("\n\n[ Use UP and DOWN arrow to select an option ]");
        ch = getch();
        if(ch == 72)
            choice--;
        else if(ch == 80)
            choice++;
        if(choice<1)
            choice = 1;
        else if(choice>4)
            choice = 4;
    }
    return choice;
}

int main()
{
    int choice=1;
    char ch;
    struct node* tempnode;
    struct list l;
    l.head = NULL;

    while(choice!=4){
        choice = getChoice(choice);
        switch(choice){
            case 1: tempnode = createNode();
                    push(&l,tempnode);
                    printf("\n\n New node pushed SUCCESSFULLY.");
                    displayList(&l);
                    break;
            case 2: tempnode = pop(&l);
                    if(tempnode!=NULL)
                        printf("\n\n Node popped SUCCESSFULLY\n Deleted value: %d",tempnode->data);
                    displayList(&l);
                    break;
            case 3: displayList(&l);
                    break;
            case 4: printf("\n\n");
        }
    }
    return 0;
}