struct BST
{
    int a;struct BST *r,*l;
}*root,*p,*q,*t,*s,*temp,*temp2,*nt,*w;
int find(int data)
{temp=root;temp2=NULL;
    while(temp->a!=data)
    {if(temp==NULL)
        {printf("not found");
                return 0;}
        temp2=temp;
        if(data < temp->a)
            temp=temp->l;
        if(data > temp->a)
            temp=temp->r;}
    return 1;
}
void delete()
{int v;
    printf("nenter which you want to delete:");
    scanf("%d",&v);
    if(root==NULL)
    printf("tree is empty");
    if(find(v))
    {if(temp==root && temp->l==NULL && temp->r==NULL)
        {free(temp);
            printf("there are no node avalable now");
            root=NULL;}
        else
        {if(temp->r==NULL)
            nt=temp->l;
            else
            {
            nt=temp->r;
            w=nt;
                while(w->l!=NULL)
                    w=w->l;
            w->l=temp->l;
            }
            if(temp==root)
            {
                root=nt;
            }
            else
            {
            if(temp2->l==temp)
            temp2->l=nt;
            else
            temp2->r=nt;
            }
        }
    }
}
void inorder(struct BST *x)
{
    if(root)
    {
    if(x->l!=NULL)inorder(x->l);
    printf("  %d",x->a);
    if(x->r!=NULL) inorder(x->r);
    }
    else
    printf("tree is empty");
}
void preorder(struct BST *y)
{
    if(root)
    {
    printf("  %d",y->a);
    if(y->l!=NULL) preorder(y->l);
    if(y->r!=NULL) preorder(y->r);
    }
    else
    printf("tree is empty");
}
void postorder(struct BST *z)
{
    if(root)
    {
    if(z->l!=NULL) postorder(z->l);
    if(z->r!=NULL) postorder(z->r);
    printf("  %d",z->a);
    }
    else
    printf("tree is empty");
}

void main()
{
    root=NULL;
    printf("enter your choice:n1.enter  n2.inordern3.preordern4.postordern5.deleatn6.exit");
    while(1)
    {
          int ch,fl=0;
          printf("n enter your choice:");
          scanf("%d",&ch);
        switch(ch)
        {
            case 1:
            p=(struct BST*)malloc(sizeof (struct BST));
            printf("nenter the node to enter:");
            scanf("%d",&p->a);
            p->r=p->l=NULL;
              if(root==NULL)
                root=p;
             else
             {
                q=root;
                while(q!=NULL)
                {
                    if(p->a==q->a)
                    {
                    printf("Not possible to enter");
                    fl=1;
                    break;
                    }
                    t=q;
                    if(p->a < q->a)
                    {
                    q=q->l;
                    }
                    else
                    q=q->r;
                }
            if(fl==0)
            {
            if(p->a < t->a) t->l=p;
            else t->r=p;
            }
            break;
            case 2:s=root;
            printf("nthe Inorder representation is :");
            inorder(s);
            break;
            case 3:s=root;
            printf("nthe Preorder representation is :");
            preorder(s);
            break;
            case 4:s=root;
            printf("nthe Postorder representation is :");
            postorder(s);
            break;
            case 5:
                delete();
            printf("deleted sucessfully");
                break;
            case 6:exit(0);
            default :printf("wrong choice");
            }
        }
    }
}