#include <iostream>
#include <cstdlib>
using namespace std;

#include "ex5-9list.h"

List::List()
{
	top_ = 0;
}


List::~List()
{
	Node* temp = top_;
	while (temp != 0) {
		top_ = top_ -> next_;
		delete temp;
		temp = top_;
	}
}

void List::push(int item)
{
	Node* temp = new Node(item,top_);
	if (!temp) {
		cerr << "Unable to allocate memory for a Node.  Exiting ...\n";
		exit(-1);
	}
	else {
		top_ = temp;
	}
}


int List::pop()
{
	Node* temp = top_;
	top_ = top_->next_;
	int value = temp->data_;
	delete temp;
	return value;
}


int List::top() const
{
	return top_ -> data_;
}


void List::print() const
{
	Node* temp = top_;
	while (temp != 0) {
		cout << temp -> data_ << ' ';
		temp = temp -> next_;
	}
	cout << endl;
}


Node*	List::find(int item)
{
	Node* temp = top_;
	while (temp != 0) {
		if (temp->data_ == item) return temp;
		temp = temp -> next_;
	}
	return 0;
}


bool List::remove(int item)
{
	if (!find(item)) {
		cerr << item << " is not in the List\n";
		return false;
	}
	Node* temp1 = top_;
	Node* temp2;
	if (top_->data_ == item) {
		top_ = top_ -> next_;
		delete temp1;
		return true;
	}
	while (temp1->next_->data_ != item) {
		temp2 = temp1;
		temp1 = temp1 -> next_;
	}
	temp2 = temp1 -> next_;
	temp1->next_ = temp2 -> next_;
	delete temp2;
	return true;
}