list.hpp

/* Copyright: (c) Kayne Ruse 2014
 * 
 * This software is provided 'as-is', without any express or implied
 * warranty. In no event will the authors be held liable for any damages
 * arising from the use of this software.
 * 
 * Permission is granted to anyone to use this software for any purpose,
 * including commercial applications, and to alter it and redistribute it
 * freely, subject to the following restrictions:
 * 
 * 1. The origin of this software must not be misrepresented; you must not
 * claim that you wrote the original software. If you use this software
 * in a product, an acknowledgment in the product documentation would be
 * appreciated but is not required.
 * 
 * 2. Altered source versions must be plainly marked as such, and must not be
 * misrepresented as being the original software.
 * 
 * 3. This notice may not be removed or altered from any source
 * distribution.
*/
#ifndef LIST_HPP_
#define LIST_HPP_

template<typename T>
class Node {
public:
	Node() = default;
	~Node() = default;

	Node<T>* SetNext(Node<T>* ptr) { return next = ptr; }
	Node<T>* GetNext() { return next; }

	T& operator*() { return element; }

private:
	Node<T>* next = nullptr;
	T element;
};

template<typename T>
class List {
public:
	List() = default;
	~List() = default;

	Node<T>* Push(Node<T>* slab) {
		//recieve any number of cards
		if (!slab) return nullptr;
		Node<T>* tmpHead = head;
		head = slab;
		while (slab->GetNext()) slab = slab->GetNext();
		slab->SetNext(tmpHead);
	}

	Node<T>* Peek(int index = 0) {
		Node<T>* it = head;
		while (it && index--) it = it->GetNext();
		return it;
	}

	Node<T>* Pop(int index = 0, int count = 1) {
		//nothing to return
		if (!head) return nullptr;

		if (index == 0) {
			//returning the first card
			Node<T>* ret = head, *tail = head;
			while(tail->GetNext() && --count) tail = tail->GetNext();
			head = tail->GetNext();
			tail->SetNext(nullptr);
			return ret;
		}

		//locate the slab
		Node<T>* prev = head;
		while(prev && --index) prev = prev->GetNext();
		Node<T>* tail = prev;
		while(tail && count--) tail = tail->GetNext();

		//prev or tail overruns the list
		if (!prev) return nullptr;
		if (!tail) {
			Node<T>* ret = prev->GetNext();
			prev->SetNext(nullptr);
			return ret;
		}

		//cut the slab out
		Node<T>* ret = prev->GetNext();
		prev->SetNext(tail->GetNext());
		tail->SetNext(nullptr);

		return ret;
	}

	int GetSize() {
		int ret = 0;
		for (Node<T>* ptr = head; ptr; ptr = ptr->GetNext()) ++ret;
		return ret;
	}

private:
	Node<T>* head = nullptr;
};

#endif