#include <stdio.h>
#include <conio.h>
#include <stdlib.h>
#include <alloc.h>
#include <iostream.h>

typedef enum {false,true} bool;

typedef struct record* ptr ;
struct record
{
	int data;
	ptr next;
};

ptr root,node;
char choice;

void create()
{
	int n=1;
	root=NULL;
	while (n!=0)
	{
		cout << "enter no: ";
		cin >> n;
		node = new record;
		node->data=n;
		node->next=root;
		root=node;
	}
}

void display()
{
	node=root;
	while (node!=NULL)
	{
		cout << node->data<<' ';
		node=node->next;
	}
}

void insert()
{
	int i,n;
	ptr temp;
	cout << "Enter no to insert: ";
	cin >> i;
	cout << "Insert after(0 for at head): ";
	cin >> n;
	node=root;
	if (n==0)
	{
		temp=new record;
		root=temp;
		root->data=i;
		temp->next=node;
	}

	else
	{
		while (node->data!=n) node=node->next;
		temp=new record;
		temp->data=i;
		temp->next=node->next;
		node->next=temp;
	}
}

void del()
{
	int n;
	cout << "Enter the no to delete (0 for head): ";
	cin >> n;
	ptr back;
	back=node=root;
	if (n==0)
	{
		root=node->next;
		delete node;
	}
	else while (node->data!=n)
	{
		back=node;
		node=node->next;
	}
	back->next=node->next;
	delete node;
}


void search()
{
	int n;
	bool found;
	cout << "enter no to find: ";
	cin >> n;
	node=root;
	while ((node!=NULL)||(found==0))
	{
		if (node->data==n) found=true;
		node=node->next;
	};
	if (found==true) cout << "found";
	else cout<<"not found";
}

void menu()
{
	cout<<"\n\nEnter a choice\n";
	cout<<"1:display,s:search,i:insert,d:delete,x:exit ";
	cin >> choice;
}



int main()
{
	clrscr();
	create();
	do
	{
		menu();
		switch (choice)
		{
			case '1':display();break;
			case 's':search();break;
			case 'i':insert();break;
			case 'd':del();break;
		}
	}
	while (choice!='x');
	return 0;
}