红黑树

#pragma onceenum Colour{RED,BLACK,};template <class K, class V>struct RBTreeNode{// Key/ValueK _key;V _value;// 节点链接RBTreeNode<K, V>* _left;RBTreeNode<K, V>* _right;RBTreeNode<K, V>* _parent;// 颜色Colour _colour;RBTreeNode(const K& key, const V& value, Colour colour = RED):_key(key),_value(value),_left(NULL),_right(NULL),_parent(NULL),_colour(colour){}};template<class K, class V>class RBTree{typedef RBTreeNode<K, V> Node;public:RBTree():_root(NULL){}public:bool Insert(const K& key, const V& value){// 1.根节点则直接创建节点if (_root == NULL){// 根节点是黑色的_root = new Node(key, value, BLACK);return true;}// 2.查找插入的位置，并插入节点Node* parent = NULL;Node* cur = _root;while (cur){if (cur->_key < key){parent = cur;cur = cur->_right;}else if (cur->_key > key){parent = cur;cur = cur->_left;}else{return false;}}cur = new Node(key, value);if (parent->_key > key){parent->_left = cur;cur->_parent = parent;}else{parent->_right = cur;cur->_parent = parent;}// 3.根据颜色调整结构及颜色，满足红黑树的规则while(cur != _root && parent->_colour == RED){Node* grandfather = parent->_parent;// 父节点是祖父的左孩子if (parent == grandfather->_left){// 1.叔叔节点存在且为红色--情况1// 2.无叔叔节点/或叔叔节点为黑--情况2// 3.cur为p的右孩子，则以p为轴，进行左单旋转，转换为情况2Node* uncle = grandfather->_right;if(uncle && uncle->_colour == RED){parent->_colour = BLACK;uncle->_colour = BLACK;grandfather->_colour = RED;cur = grandfather;parent = cur->_parent;}else{if(cur == parent->_right){_RotateL(parent);swap(cur, parent);}grandfather->_colour = RED;parent->_colour = BLACK;_RotateR(grandfather);}}else{Node* uncle = grandfather->_left;if(uncle && uncle->_colour == RED){parent->_colour = BLACK;uncle->_colour = BLACK;grandfather->_colour = RED;cur = grandfather;parent = cur->_parent;}else{if(cur == parent->_left){_RotateR(parent);swap(cur, parent);}grandfather->_colour = RED;parent->_colour = BLACK;_RotateL(grandfather);}}}_root->_colour = BLACK;return true;}void _RotateL(Node* parent){// 提升右孩子Node* subR = parent->_right;Node* subRL = subR->_left;// 1.右孩子的左子树交给父节点的右parent->_right = subRL;if (subRL)subRL->_parent = parent;// 2.父节点变成右孩子的左subR->_left = parent;subR->_parent = parent->_parent;Node* ppNode = parent->_parent;parent->_parent = subR;if (ppNode == NULL){_root = subR;subR->_parent = NULL;}else{if (ppNode->_left == parent)ppNode->_left = subR;elseppNode->_right = subR;subR->_parent = ppNode;}}void _RotateR(Node*& parent){// 提升左孩子Node* subL = parent->_left;Node* subLR = subL->_right;parent->_left = subLR;if (subLR)subLR->_parent = parent;subL->_right = parent;subL->_parent = parent->_parent;Node* ppNode = parent->_parent;parent->_parent = subL;parent = subL;if (ppNode == NULL){_root = subL;subL->_parent = NULL;}else{if (ppNode->_left == parent)ppNode->_left = subL;elseppNode->_right = subL;subL->_parent = ppNode;}}void InOrder(){_InOrder(_root);cout<<endl;}bool IsBlance(){if (_root == NULL)return true;if (_root->_colour == RED)return false;// 计算一条路径上黑色节点的数量int k = 0;Node* cur = _root;while(cur){if (cur->_colour == BLACK)++k;cur = cur->_left;}int count = 0;return _IsBlance(_root, k, count);}bool _IsBlance(Node* root, const int k, int count){if (root == NULL)return true;// 3.检查是否存在连续的红节点if (root->_colour == RED && root->_parent->_colour == RED){cout<<"连续红节点"<<root->_key<<endl;return false;}if (root->_colour == BLACK){++count;}// 4.检查黑色节点的数量是否相等if (root->_left ==  NULL&& root->_right == NULL&& k != count){cout<<"黑色节点的数量不相等"<<root->_key<<endl;return false;}return _IsBlance(root->_left, k, count)&& _IsBlance(root->_right, k, count);}void _InOrder(Node* root){if (root == NULL){return;}_InOrder(root->_left);cout<<root->_key<<" ";_InOrder(root->_right);}protected:Node* _root;};void TestRBTree(){RBTree<int, int> t1;int a[] = {10, 7, 8, 15, 5, 6, 11, 13, 12};for (size_t i = 0; i < sizeof(a)/sizeof(int); ++i){t1.Insert(a[i], i);}t1.InOrder();cout<<"t1 IsBlance:"<<t1.IsBlance()<<endl;}