链表的模板实现

BaseList.h

#pragma once

template <class T>
class BaseList {
public:
	typedef size_t pos;

	virtual void clear() = 0;						// empty the list
	virtual bool isEmpty() = 0;						// Is empty list?
	virtual void append(const T&) = 0;				// add element in the end
	virtual void insert(const pos, const T&) = 0;	// insert element in the middle
	virtual void del(const pos) = 0;				// delete element from list
	virtual T getValue(const pos) = 0;				// return the value in the position
	virtual void setValue(const pos, const T&) = 0;	// modify the value at position
	virtual pos getPosition(const T&) = 0;			// get the position of value T
};

LinkList.h

#pragma once

#include <iostream>

#include "BaseList.h"

template <class T>
class Node {
public:
	T val;
	Node* next;

	Node(const T& val, Node *p = nullptr)
		: val(val), next(p) {}

	Node(Node *p = nullptr)
		:next(p) {}
};

template <class T>
class LinkList : public BaseList<T> {
private:
	Node<T>* head;

	Node<T>* getNodePosition(BaseList<T>::pos p) {
		if (p == -1) {
			return head;
		}
		Node<T>* tmpNode = head->next;
		for (int i = 0; i < p; i++) {
			tmpNode = tmpNode->next;
		}
		return tmpNode;
	}

	Node<T>* getTail() {
		if (!head->next) {
			return head;
		}
		Node<T>* itr = head->next;
		while (itr->next) {
			itr = itr->next;
		}
		return itr;
	}

	void checkLinkList() {
		if (!head->next) {
			throw std::exception("Empty list");
		}
		return;
	}

public:
	LinkList()
		: head(new Node<T>()) {};
	~LinkList() {
		Node<T>* itr = head->next;
		while (itr) {
			Node<T> *temp = itr;
			itr = itr->next;
			delete temp;
		}
	}

	virtual void clear() override {
		checkLinkList();
		Node<T>* itr = head->next;
		while (itr != nullptr) {
			Node<T>* temp = itr;
			delete temp;
			itr = itr->next;
		}
		head = nullptr;
	}

	virtual bool isEmpty() override {
		return head->next == nullptr;
	}

	virtual void append(const T& val) override {
		Node<T>* newNode = new Node<T>(val);
		if (!head->next) {
			head->next = newNode;
			return;
		}
		Node<T>* tail = getTail();
		tail->next = newNode;
		return;
	}

	virtual void insert(const BaseList<T>::pos p, const T& val) override {
		if (!head->next) {
			if (p == 0) {
				append(val);
			}
			else {
				throw std::exception("Empty list");
			}
		}
		Node<T>* insertPos = getNodePosition(p);
		Node<T>* newNode = new Node<T>(val);
		newNode->next = insertPos->next;
		insertPos->next = newNode;
		return;
	}

	virtual void del(const BaseList<T>::pos p) override {
		checkLinkList();
		Node<T>* beforeDelPos = getNodePosition(p - 1);
		if (beforeDelPos) {
			if (beforeDelPos->next) {
				Node<T>* deleteNode = beforeDelPos->next;
				beforeDelPos->next = deleteNode->next;
				delete deleteNode;
				return;
			}
			throw std::exception("Delete node exceed list tail");
		}
		throw std::exception("Invalid position to delete");
	}

	virtual T getValue(const BaseList<T>::pos p) override {
		checkLinkList();
		Node<T>* readPos = getNodePosition(p);
		return readPos->val;
	}

	virtual void setValue(const BaseList<T>::pos p, const T& val) override {
		checkLinkList();
		Node<T>* writePos = getNodePosition(p);
		writePos->val = val;
		return;
	}

	virtual BaseList<T>::pos getPosition(const T& val) override {
		checkLinkList();
		int count = 0;
		Node<T>* itr = head->next;
		while (itr->val != val) {
			itr = itr->next;
			++count;
		}
		return count;
	}

	void print() {
		Node<T>* itr = head->next;
		int count = 0;
		while (itr) {
			std::cout << "Node Index: " << count++ << '\t';
			std::cout << "Node value: " << itr->val << std::endl;
			itr = itr->next;
		}
		return;
	}
};

main.cpp

// LinkList.cpp : This file contains the 'main' function. Program execution begins and ends there.
//

#include <iostream>

#include "LinkList.h"

using namespace std;

int main()
{
    LinkList<int> linklist;

    cout << "Enter the count of nodes you want to append" << endl;
    int count;
    cin >> count;
    while (count--) {
        cout << "Enter the value of node" << endl;
        int val;
        cin >> val;
        linklist.append(val);
    }
    linklist.print();

    cout << "Enter the node index you want to delete" << endl;
    int delIndex = 0;
    cin >> delIndex;
    linklist.del(delIndex);
    linklist.print();

    cout << "Enter the node index you want to insert" << endl;
    int insertIndex;
    cin >> insertIndex;
    cout << "Enter the node value you want to insert" << endl;
    int nodeVal;
    cin >> nodeVal;
    linklist.insert(insertIndex, nodeVal);
    linklist.print();

    return 0;
}