doublylink

#include<stdio.h>

typedef struct mylist
{
    int data;
    struct mylist *next;
    struct mylist *prev;
}node;

void insert(node *p, int data){
    while(p -> next != NULL){
        p = p -> next;
    }
    p -> next = (node *)malloc(sizeof(node));
    p -> next -> prev = p;
    p -> next -> data = data;
    p -> next -> next = NULL;
}

int search(node *p, int key){
    p = p -> next;
    while(p != NULL){
        if(p -> data == key){
            return 1;
        }
    p = p -> next;
    }
    return 0;
}

void delete(node *p, int data){
    while(p -> next != NULL)
    {
        if(p -> next -> data == data)
        {
            p -> next = p -> next -> next;
            p -> next -> prev = p;
            free(p -> next);
            return 0;
        }
    }

}

void display(node *p)
{
    while(p -> next != NULL)
    {
        printf("%d\n",p -> next -> data);
        p = p -> next;
    }
}
int main(){


    node *start = (node *)malloc(sizeof(node));
    start -> next = NULL;
    start -> prev = NULL;

    printf("1. Insert\n");
    printf("2. Delete\n");
    printf("3. Print\n");
    printf("4. Search\n");

    while(1){
        int query, data;
        scanf("%d",&query);

        switch(query){
            case 1:
            scanf("%d",&num);

            insert(start,data);
            break;

            case 2:
            scanf("%d",&data);
            delete(start,data);
            break;

            case 3:
            printf("The list is ");
            display(start);
            printf("\n");
            break;

            case 4:
            scanf("%d",&data);
            int status = search(start,data);

                if(status)
                    printf("Element Found\n");
                else
                    printf("Element Not Found\n");
        }
    }
}