enum Color {
	BLACK,
	RED
};

template<class T>
struct RBTreeNode
{
	RBTreeNode<T>* _left;
	RBTreeNode<T>* _right;
	RBTreeNode<T>* _parent;

	Color _col;
	T _data;

	RBTreeNode(const T& data)
		: _left(nullptr)
		, _right(nullptr)
		, _parent(nullptr)
		, _col（RED)
		，_data(data)
	{}
};

// T->K  set
// T->pair<const K, V> map
template<class K, class T, class KeyOfT>
class RBTree
{
	typedef RBTreeNode<T> Node;
public:
	typedef RBTreeIterator<T, T&, T*> iterator;
	typedef RBTreeIterator<T, const T&, const T*> const_iterator;

	iterator begin();
	iterator end();

	RBTree()
		:_root(nullptr)
	{}

	// 拷貝構(gòu)造和賦值重載
	// 析構(gòu)

	Node* Find(const K& key);

	pair<iterator, bool> Insert(const T& data)
	{
		if (_root == nullptr)
		{
			_root = new Node(data);
			_root->_col = BLACK;
			return make_pair(iterator(_root), true);
		}

		Node* parent = nullptr;
		Node* cur = _root;

		KeyOfT kot;
		while (cur)
		{
			if (kot(cur->_data) < kot(data))
			{
				parent = cur;
				cur = cur->_right;
			}
			else if (kot(cur->_data) > kot(data))
			{
				parent = cur;
				cur = cur->_left;
			}
			else
			{
				return make_pair(iterator(cur), false);
			}
		}

		// 新增節(jié)點(diǎn)，顏色是紅色，可能破壞規(guī)則3，產(chǎn)生連續(xù)紅色節(jié)點(diǎn)
		cur = new Node(data);
		Node* newnode = cur;
		cur->_col = RED;

		if (kot(parent->_data) < kot(data))
		{
			parent->_right = cur;
			cur->_parent = parent;
		}
		else
		{
			parent->_left = cur;
			cur->_parent = parent;
		}

		// 控制近似平衡
		while (parent && parent->_col == RED)
		{
			Node* grandfather = parent->_parent;
			if (parent == grandfather->_left)
			{
				Node* uncle = grandfather->_right;
				// 情況一：uncle存在且為紅，進(jìn)行變色處理，并繼續(xù)往上更新處理
				if (uncle && uncle->_col == RED)
				{
					parent->_col = uncle->_col = BLACK;
					grandfather->_col = RED;

					cur = grandfather;
					parent = cur->_parent;
				} // 情況二+三：uncle不存在，或者存在且為黑，需要旋轉(zhuǎn)+變色處理
				else
				{
					// 情況二：?jiǎn)涡?變色
					if (cur == parent->_left)
					{
						RotateR(grandfather);
						parent->_col = BLACK;
						grandfather->_col = RED;
					}
					else // 情況三：雙旋 + 變色
					{
						RotateL(parent);
						RotateR(grandfather);
						cur->_col = BLACK;
						grandfather->_col = RED;
					}

					break;
				}
			}
			else  // (parent == grandfather->_right)
			{
				Node* uncle = grandfather->_left;
				if (uncle && uncle->_col == RED)
				{
					parent->_col = uncle->_col = BLACK;
					grandfather->_col = RED;

					cur = grandfather;
					parent = cur->_parent;
				}
				else
				{
					if (parent->_right == cur)
					{
						RotateL(grandfather);
						parent->_col = BLACK;
						grandfather->_col = RED;
					}
					else
					{
						RotateR(parent);
						RotateL(grandfather);
						cur->_col = BLACK;
						grandfather->_col = RED;
					}

					break;
				}
			}
		}

		_root->_col = BLACK;
		return make_pair(iterator(newnode), true);
	}

	void RotateR(Node* parent);
	void RotateL(Node* parent);

private:
	Node* _root;
};

template<class K, class V>
struct RBTreeNode
{
	RBTreeNode<K, V>* _left;
	RBTreeNode<K, V>* _right;
	RBTreeNode<K, V>* _parent;

	Colour _col;
	pair<K, V> _kv;

	RBTreeNode(const pair<K, V>& kv)
		:_left(nullptr)
		, _right(nullptr)
		, _parent(nullptr)
		, _col(RED)
		, _kv(kv)
	{}
};

template<class K, class V>
class RBTree
{
	typedef RBTreeNode<K, V> Node;
public:
	RBTree()
		:_root(nullptr)
	{}

	bool Insert(const pair<K, V>& kv);

	void RotateR(Node* parent);
	void RotateL(Node* parent);

	void _InOrder(Node* root)
	{
		if (root == nullptr)
		{
			return;
		}

		_InOrder(root->_left);
		cout << root->_kv.first << " ";
		_InOrder(root->_right);
	}

	void InOrder()
	{
		_InOrder(_root);
		cout<<endl;
	}

	bool CheckRED_RED(Node* cur)
	{
		if (cur == nullptr)
		{
			return true;
		}

		if (cur->_col == RED && cur->_parent->_col == RED)
		{
			cout << "違反規(guī)則三，存在連續(xù)的紅色節(jié)點(diǎn)" << endl;
			return false;
		}

		return CheckRED_RED(cur->_left)
			&& CheckRED_RED(cur->_right);
	}

	// 檢查每條路徑黑色節(jié)點(diǎn)的數(shù)量
	bool CheckBlackNum(Node* cur, int blackNum, int benchmark) {
		if (cur == nullptr) {
			if (blackNum != benchmark){
				cout << "違反規(guī)則四：黑色節(jié)點(diǎn)的數(shù)量不相等" << endl;
				return false;}
			return true;
		}

		if (cur->_col == BLACK)
			++blackNum;

		return CheckBlackNum(cur->_left, blackNum, benchmark)
			&& CheckBlackNum(cur->_right, blackNum, benchmark);
	}

	bool IsBalance()
	{
		if (_root == nullptr)
		{
			return true;
		}

		if (_root->_col == RED)
		{
			cout << "根節(jié)點(diǎn)是紅色，違反規(guī)則二" << endl;
			return false;
		}

		// 算出最左路徑的黑色節(jié)點(diǎn)的數(shù)量作為基準(zhǔn)值
		int benchmark = 0;
		Node* cur = _root;
		while (cur)
		{
			if (cur->_col == BLACK)
			{
				++benchmark;
			}

			cur = cur->_left;
		}

		int blackNum = 0;
		return CheckRED_RED(_root) && CheckBlackNum(_root, blackNum, benchmark);
	}

private:
	Node* _root;
};

void TestRBTree1()
{
	const int n = 1000000;
	vector<int> a;
	a.reserve(n);
	srand(time(0));
	for (size_t i = 0; i < n; ++i)
	{
		a.push_back(rand());
	}

	RBTree<int, int> t1;
	for (auto e : a)
	{
		t1.Insert(make_pair(e, e));
	}

	cout << t1.IsBalance() << endl;
	//t1.InOrder();
}

	typedef RBTreeIterator<T, T&, T*> iterator;
	typedef RBTreeIterator<T, const T&, const T*> const_iterator;

	iterator begin()
	{
		Node* left = _root;
		while (left && left->_left)
		{
			left = left->_left;
		}

		//return left
		return iterator(left);
	}

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

template<class T, class Ref, class Ptr>
struct RBTreeIterator
{
	typedef RBTreeNode<T> Node;
	typedef RBTreeIterator<T, Ref, Ptr> Self;
	Node* _node;
	RBTreeIterator(Node* node = nullptr)
		:_node(node)
	{}

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

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

	Self& operator--()
	{
		// 跟++基本是反過(guò)來(lái)
		return *this;
	}

	Self& operator++()
	{
		if (_node->_right)
		{
			// 右子樹(shù)中序第一個(gè)節(jié)點(diǎn)，也就是右子樹(shù)的最左節(jié)點(diǎn)
			Node* subLeft = _node->_right;
			while (subLeft->_left)
			{
				subLeft = subLeft->_left;
			}

			_node = subLeft;
		}
		else
		{
			// 當(dāng)前子樹(shù)已經(jīng)訪(fǎng)問(wèn)完了，要去找祖先訪(fǎng)問(wèn)，沿著到根節(jié)點(diǎn)的路徑往上走，
			// 找孩子是父親左的那個(gè)父親節(jié)點(diǎn)
			Node* cur = _node;
			Node* parent = cur->_parent;
			while (parent && parent->_right == cur)
			{
				cur = parent;
				parent = parent->_parent;
			}

			_node = parent;
		}

		return *this;
	}

	bool operator!=(const Self& s) const
	{
		return _node != s._node;
	}

	bool operator==(const Self& s) const
	{
		return _node == s._node;
	}
};

#pragma once
#include "RBTree.h"

namespace MyMap
{
	template < class K, class V>
	class map
	{
		struct MapKeyOfT
		{
			const K& operator()(const pair<const K, V>& kv)
			{
				return kv.first;
			}
		};
	public:
		typedef typename RBTree<K, pair<const K, V>, MapKeyOfT>::iterator iterator;

		iterator begin()
		{
			return _t.begin();
		}

		iterator end()
		{
			return _t.end();
		}

		pair<iterator, bool> insert(const pair<const K, V>& kv)
		{
			return _t.Insert(kv);
		}

		V& operator[](const K& key)
		{
			pair<iterator, bool> ret = _t.Insert(make_pair(key, V()));
			return ret.first->second;
		}
	private:
		RBTree<K, pair<const K, V>, MapKeyOfT> _t;
	};

	void test_map()
	{
		map<string, string> dict;
		dict.insert(make_pair("sort", "排序"));
		dict.insert(make_pair("string", "字符串"));
		dict.insert(make_pair("debug", "找蟲(chóng)子"));
		dict.insert(make_pair("set", "集合"));

		map<string, string>::iterator it = dict.begin();
		while (it != dict.end())
		{
			cout << it->first << ":" << it->second << endl;
			++it;
		}
		cout << endl;
	}
}

#pragma once
#include "RBTree.h"

namespace MySet
{
	template < class K>
	class set
	{
		struct SetKeyOfT
		{
			const K& operator()(const K& key)
			{
				return key;
			}
		};
	public:
		typedef typename RBTree<K, K, SetKeyOfT>::iterator iterator;

		iterator begin()
		{
			return _t.begin();
		}

		iterator end()
		{
			return _t.end();
		}

		pair<iterator, bool> insert(const K& key)
		{
			return _t.Insert(key);
		}
	private:
		RBTree<K, K, SetKeyOfT> _t;
	};

	void test_set()
	{
		set<int> s;
		s.insert(1);
		s.insert(3);
		s.insert(7);
		s.insert(2);
		s.insert(12);
		s.insert(22);
		s.insert(2);
		s.insert(23);
		s.insert(-2);
		s.insert(-9);
		s.insert(30);

		set<int>::iterator it = s.begin();
		while (it != s.end())
		{
			cout << *it << " ";
			++it;
		}
		cout << endl;

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