LinkedList

#include<stdio.h>
#include<conio.h>
#include<stdlib.h>
struct Node{
    int data;
    struct Node* next;
}*head;
void insertatfirst(int ele){
    struct Node *new = (struct Node*)malloc(sizeof(struct Node));
    new->data = ele;
    if(head==NULL){
        new->next = NULL;
    }
    else{
        new->next = head;
    }
    head = new;
}
void insertatlast(int ele){
    
    struct Node *temp = (struct Node*)malloc(sizeof(struct Node));
    struct Node *new = (struct Node*)malloc(sizeof(struct Node));

    new->data = ele;
    temp = head;
    if(head==NULL){
        new->next = NULL;
        head = new;
    }
    else{
        while(temp->next!=NULL){
            temp = temp->next;
        }
    }
    temp->next = new;
    new->next = NULL;
}

int deletefirst(){
    struct Node *temp = (struct Node*)malloc(sizeof(struct Node));
    if(head==NULL){
        printf("Underflow!!");
        return 0;
    }
    else{
        temp = head;
        head = head->next;
        return temp->data;
    }
}
int deletelast(){
    struct Node *temp = (struct Node*)malloc(sizeof(struct Node));
    struct Node *prev = (struct Node*)malloc(sizeof(struct Node));
    if(head==NULL){
        printf("Underflow!!");
        return 0;
    }
    else if(head->next=NULL){
        head = NULL;
        return 0;

    }
    else{
        temp = head;
        while(temp->next!=NULL){
            prev = temp;
            temp = temp->next;
        }
        
        prev->next = NULL;
        
        return temp->data;
    }
}
void display(){
    struct Node *temp = (struct Node*)malloc(sizeof(struct Node));
    temp = head;
    printf("\n");
    while(temp!=NULL){
        printf("%d -> ",temp->data);
        temp = temp->next;
    }
    printf("NULL");
}
void main(){
    char yn;
    int ch,ele,data;
    do{
        printf("\n 1: For Insert at Beginning \n 2: For Insert at end\n 3: For Delete at Beginning \n 4: For Delete at end\n 5: For Display\n \n Your choice: ");
        scanf("%d",&ch);
        switch(ch){
            case 1: printf("\nEnter Element you want to Insert: ");
                    scanf("%d",&ele);
                    insertatfirst(ele);
                    break;
            case 2: printf("\nEnter Element you want to Insert: ");
                    scanf("%d",&ele);
                    insertatlast(ele);
                    break;
            
            case 3:data = deletefirst();
                    printf("Deleted data is %d",data);
                    break;
            case 4:data = deletelast();
                    printf("Deleted data is %d",data);
                    break;
            case 5:display();
                    break;

            default:
                    printf("Wrong choice!");
        }
        printf("\n\nDo you want to continue? Enter Y for yes: ");
        scanf(" %c",&yn);

    }while(yn=='Y'||yn=='y');
    getch();    //for holding the screen
}