/*Coded By Md Shoriful Islam 
ID: 12108048
Batch:13*/

#include<stdio.h>
#include<stdlib.h>

struct node
{
    int sa_info;
    struct node *NEXT;
};
struct node *pos1 = NULL;
struct node *LAST = NULL;

void sa_input(int);
int sa_del(int);
void sa_output(void);
struct node *sa_find (int);
int main()
{
    int n1, n2, select;
    struct node *location;

    while(1)
    {

        printf("Select an option");
        printf("\n1 - Insert");
        printf("\n2 - Delete");
        printf("\n3 - Search");
        printf("\n4 - Print");
        printf("\n5 - Exit");
        printf("\nEnter your choice: ");
        scanf("%d", &select);
        switch(select)
        {
        case 1:
        {
            printf("\nEnter the element to be inserted into the linked list: ");
            scanf("%d",&n1);
            sa_input(n1);
            printf("\n%d successfully inserted into the linked list!",n1);

            break;
        }
        case 2:
        {
            printf("\nEnter the element to be deleted from the linked list: ");
            scanf("%d",&n1);
            n2=sa_del(n1);
            if(n2==-9999)
                printf("\n%d is not present in the linked list\n",n1);
            else printf("\nElement %d successfully deleted from the linked list\n",n2);

            break;
        }
        case 3:
        {
            printf("\nEnter the element to be searched: ");
            scanf("%d",&n1);
            location=sa_find(n1);
            if(location==NULL)
                printf("\n%d is not present in the linked list\n",n1);
            else
            {
                if(location==LAST)
                    printf("\nElement %d is the last element in the list",n1);
                else
                    printf("\nElement %d is present before element %d in the linked list\n",n1,(location->NEXT)->sa_info);
            }

            break;
        }
        case 4:
        {
            sa_output();

            break;
        }
        case 5:
        {
            printf("\nEND");
            exit(1);
            break;
        }
        default:
        {
            printf("\nIncorrect choice. Please try again.");

            break;
        }
        }
    }
}
void sa_input(int value)
{

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

    pr->sa_info = value;

    if(pos1==NULL)
    {
        pos1 = LAST = pr;
        pr->NEXT=NULL;
    }
    else
    {
        LAST->NEXT = pr;
        pr->NEXT = NULL;
        LAST = pr;
    }
}

int sa_del(int value)
{
    struct node *LOC,*TEMP;
    int i;
    **value;
    LOC=sa_find(i);
    if(LOC==NULL)
        return(-9999);
    if(LOC==pos1)
    {
        if(pos1==LAST)
            pos1=LAST=NULL;
        else
            pos1=pos1->NEXT;
        return(value);
    }
    for(TEMP=pos1; TEMP->NEXT!=LOC; TEMP=TEMP->NEXT)
        ;
    TEMP->NEXT=LOC->NEXT;
    if(LOC==LAST)LAST=TEMP;
    return(LOC->sa_info);
}

struct node *sa_find (int value)
{
    struct node *pr;
    if(pos1==NULL)
        return(NULL);

    for(pr=pos1; pr!=LAST; pr=pr->NEXT)
        if(pr->sa_info==value)
            return(pr);
    if(LAST->sa_info==value)
        return(LAST);
    else
        return(NULL);
}

void sa_output()
{
    struct node *pr;
    if(pos1==NULL)
    {
        printf("\n\tEmpty List!!");
        return;
    }
    printf("\nLinked list elements:\n");
    if(pos1==LAST)
    {
        printf("\t%d",pos1->sa_info);
        return;
    }

    for(pr=pos1; pr!=LAST; pr=pr->NEXT)
        printf("%d ",pr->sa_info);
    printf("%d\n",LAST->sa_info);
}