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介绍语义标签过滤:利用标签相似性增强检索

码农K 2024-09-10 阅读 21
c++

目录

1、list的介绍和使用:

1、结构:

2、接口函数:

迭代器遍历:

增删查改:

翻转与排序:

2、list的模拟实现:

1、节点的封装:

2、迭代器的封装:

3、list的模拟实现:

1、typedef的几个类型:

2、迭代器的begin和end实现:

3、构造,拷贝构造与析构:

4、插入和删除:

5、其他:

完整代码:

3、vector和list的比较:


1、list的介绍和使用:

1、结构:

2、接口函数:

迭代器遍历:

void listtest1()
{
	list<int> lt;
	lt.push_back(1);
	lt.push_back(2);
	lt.push_back(3);
	lt.push_back(4);
	
	//list<int>::iterator it = lt.begin();
	auto it = lt.begin();
	while (it != lt.end())
	{
		cout << *it << " ";
		it++;
	}
	cout << endl;
	for (auto e : lt)
	{
		cout << e << " ";
	}
}

增删查改:

void listtest2()
{
	//创建1234的链表
	list<int> lt; 
	lt.push_back(1); 
	lt.push_back(2); 
	lt.push_back(3); 
	lt.push_back(4);

	lt.push_front(10);
	lt.push_front(20);

	for (auto e : lt)
	{
		cout << e << " ";
	}
	cout << endl;
	//定义迭代器
	list<int>::iterator it = lt.begin();
	
	//在3的前面增加一个30
	it = find(lt.begin(), lt.end(), 3);
	if (it != lt.end())
	{
		lt.insert(it, 30);

		// insert以后,it不失效
	}
	for (auto e : lt)
	{
		cout << e << " ";
	}
	cout << endl;
	//将迭代器找到3的位置
	it = find(lt.begin(), lt.end(),3); 
	//删除3,先判断,在进行删除
	if (it != lt.end())
	{
		lt.erase(it);
	}

	for (auto e : lt)
	{
		cout << e << " ";
	}
}

翻转与排序:

void listtest3()
{
	list<int> lt;
	lt.push_back(1);
	lt.push_back(3);
	lt.push_back(2);
	lt.push_back(4);

	lt.push_front(20);
	lt.push_front(10);

	for (auto e : lt)
	{
		cout << e << " ";
	}
	cout << endl;

	cout << "用算法里面的翻转后:" << endl;
	reverse(lt.begin(), lt.end());
	for (auto e : lt)
	{
		cout << e << " ";
	}
	cout << endl;

	cout << "用自己容器里面的翻转后:" << endl;
	lt.reverse();
	for (auto e : lt)
	{
		cout << e << " ";
	}
	cout << endl;

	cout << "排序后:" << endl;
	lt.sort();
	for (auto e : lt)
	{
		cout << e << " ";
	}
	cout << endl;
}

2、list的模拟实现:

1、节点的封装:

template<class T>
struct list_node
{
	list_node<T>* _next;
	list_node<T>* _prev;
	T _val;

	list_node(const T& val = T())
		:_next(nullptr)
		,_prev(nullptr)
		,_val(val)
	{}
};

2、迭代器的封装:

template<class T,class Ref,class Ptr>
struct __list_iterator
{
	typedef list_node<T> Node;
	typedef __list_iterator<T, Ref,Ptr> self;
	Node* _node;

	__list_iterator(Node* node)
		:_node(node)
	{}

	Ref operator*()
	{
		return _node->_val;
	}

	Ptr operator->()
	{
		return &_node->_val;
	}

	self& operator++()
	{
		_node = _node->_next;
		return *this;
	}

	self operator++(int)
	{
		self tmp(*this);
		_node = _node->_next;
		return tmp;
	}

	self& operator--()
	{
		_node = _node->_prev;
		return *this;
	}

	self operator--(int)
	{
		self tmp(*this);
		_node = _node->_prev;
		return tmp;
	}

	bool operator!=(const self& it) const 
	{
		return _node != it._node;
	}

	bool operator==(const self& it) const 
	{
		return _node == it._node;
	}
};

3、list的模拟实现:

1、typedef的几个类型:

	typedef list_node<T> Node;
public:
	typedef __list_iterator<T, T&, T*> iterator;
	typedef __list_iterator<T, const T&, const T*> const_iterator;

2、迭代器的begin和end实现:

iterator begin()
{
	return iterator(_head->_next);
}

iterator end()
{
	return iterator(_head);
}

const_iterator begin() const
{
	return const_iterator(_head->_next);
}

const_iterator end() const
{
	return const_iterator(_head);
}

3、构造,拷贝构造与析构:

void empty_init()
{
	_head = new Node;
	_head->_next = _head;
	_head->_prev = _head;

	_size = 0;
}

list()
{
	empty_init();
}

list(const list<T>& lt)
{
	empty_init();

	for (auto& e : lt)
	{
		push_back(e);
	}
}


~list()
{
	clear();

	delete _head;
	_head = nullptr;
}

void clear()
{
	iterator it = begin();
	while (it != end())
	{
		it = erase(it);
	}
	_size = 0;
}

4、插入和删除:

//在pos位置之前插入,最后返回新节点
iterator insert(iterator pos, const T& x)
{
	Node* cur = pos._node;
	Node* prev = cur->_prev;
	Node* newnode = new Node(x);

	prev->_next = newnode;
	newnode->_next = cur;

	cur->_prev = newnode;
	newnode->_prev = prev;

	++_size;

	return newnode;
}
//删除pos位置的节点,最后返回的是pos位置的下一个节点,注意不能删除哨兵位
//erase存在迭代器失效问题,可以用返回值来解决这个问题
iterator erase(iterator pos)
{
	assert(pos != end());

	Node* cur = pos._node;
	Node* next = cur->_next;
	Node* prev = cur->_prev;

	next->_prev = prev;
	prev->_next = next;

	delete cur;

	--_size;

	return next;
}

5、其他:

void swap(list<T>& it)
{
	std::swap(_head, it._head);
	std::swap(_size, it._size);
}

list<T>& operator=(list<T> lt)
{
	swap(lt);
	return *this;
}
size_t size()
{
	return _size;
}

完整代码:

#pragma once
#include<assert.h>

namespace ppr
{
	template<class T>
	struct list_node
	{
		list_node<T>* _next;
		list_node<T>* _prev;
		T _val;

		list_node(const T& val = T())
			:_next(nullptr)
			,_prev(nullptr)
			,_val(val)
		{}
	};

	template<class T,class Ref,class Ptr>
	struct __list_iterator
	{
		typedef list_node<T> Node;
		typedef __list_iterator<T, Ref,Ptr> self;
		Node* _node;

		__list_iterator(Node* node)
			:_node(node)
		{}

		Ref operator*()
		{
			return _node->_val;
		}

		Ptr operator->()
		{
			return &_node->_val;
		}

		self& operator++()
		{
			_node = _node->_next;
			return *this;
		}

		self operator++(int)
		{
			self tmp(*this);
			_node = _node->_next;
			return tmp;
		}

		self& operator--()
		{
			_node = _node->_prev;
			return *this;
		}

		self operator--(int)
		{
			self tmp(*this);
			_node = _node->_prev;
			return tmp;
		}

		bool operator!=(const self& it) const 
		{
			return _node != it._node;
		}

		bool operator==(const self& it) const 
		{
			return _node == it._node;
		}
	};

	template<class T>
	class list
	{
		typedef list_node<T> Node;
	public:
		typedef __list_iterator<T, T&, T*> iterator;
		typedef __list_iterator<T, const T&, const T*> const_iterator;

		iterator begin()
		{
			return iterator(_head->_next);
		}

		iterator end()
		{
			return iterator(_head);
		}

		const_iterator begin() const
		{
			return const_iterator(_head->_next);
		}

		const_iterator end() const
		{
			return const_iterator(_head);
		}
		
		void empty_init()
		{
			_head = new Node;
			_head->_next = _head;
			_head->_prev = _head;

			_size = 0;
		}

		list()
		{
			empty_init();
		}

		list(const list<T>& lt)
		{
			empty_init();

			for (auto& e : lt)
			{
				push_back(e);
			}
		}


		void swap(list<T>& it)
		{
			std::swap(_head, it._head);
			std::swap(_size, it._size);
		}

		list<T>& operator=(list<T> lt)
		{
			swap(lt);
			return *this;
		}

		~list()
		{
			clear();

			delete _head;
			_head = nullptr;
		}

		void clear()
		{
			iterator it = begin();
			while (it != end())
			{
				it = erase(it);
			}
			_size = 0;
		}

		void push_back(const T& x)
		{
			/*Node* tail = _head->_prev;
			Node* newnode = new Node(x);

			tail->_next = newnode;
			newnode->_prev = tail;

			newnode->_next = _head;
			_head->_prev = newnode;*/
			insert(end(), x);
		}

		void push_front(const T& x)
		{
			insert(begin(), x);
		}

		void pop_back()
		{
			erase(--end());
		}

		void pop_front()
		{
			erase(begin());
		}

		//在pos位置之前插入,最后返回新节点
		iterator insert(iterator pos, const T& x)
		{
			Node* cur = pos._node;
			Node* prev = cur->_prev;
			Node* newnode = new Node(x);

			prev->_next = newnode;
			newnode->_next = cur;

			cur->_prev = newnode;
			newnode->_prev = prev;

			++_size;

			return newnode;
		}
		//删除pos位置的节点,最后返回的是pos位置的下一个节点,注意不能删除哨兵位
		//erase存在迭代器失效问题,可以用返回值来解决这个问题
		iterator erase(iterator pos)
		{
			assert(pos != end());

			Node* cur = pos._node;
			Node* next = cur->_next;
			Node* prev = cur->_prev;

			next->_prev = prev;
			prev->_next = next;

			delete cur;

			--_size;

			return next;
		}

		size_t size()
		{
			return _size;
		}
	private:
		Node* _head;
		size_t _size;
	};
}

3、vector和list的比较:

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