算法导论—红黑树（还没写完，先备份一个）

#include <iostream>#include <vector>template<typename Comparable>class RBTree{private:struct RBNode{RBNode *parent;RBNode *left;RBNode *right;Comparable key;int color;RBNode(RBNode *p = nullptr, RBNode *lt = nullptr, RBNode *rt = nullptr,const Comparable ele = Comparable(), int c = BLACK):parent(p), left(lt), right(rt), key(ele), color(c){ }};RBNode *nilNode; //哨兵节点，代表叶节点和根节点的父节点RBNode *root = new RBNode(nilNode, nullptr, nullptr, Comparable(), BLACK);int currenSize = 0;enum{ RED, BLACK };void print(RBNode *t){if (t !=nilNode){print(t->left);cout << t->key << " "<<((t->color==RED)? "RED":"BLACK")<<" "<<((t==root)?"is root":"not root")<<endl;print(t->right);}}public:RBTree(){root->parent = nilNode;}void print(){print(root);}//左旋void leftRotate(RBNode *t){RBNode *y = t->right;t->right = y->left;if (y->left != nilNode)//如果y节点的左节点不为空，则应该父节点指向ty->left->parent = t;y->parent = t->parent;if (t->parent == nilNode)root = y;else if (t == t->parent->left)t->parent->left = y;elset->parent->right = y;y->left = t;t->parent = y;}//右旋void rightRotate(RBNode *t){RBNode *y = t->left;t->left = y->right;if (y->right != nilNode)y->right->parent = t;y->parent = t->parent;if (t->parent == nilNode)root = y;else if (t == t->parent->left)t->parent->left = y;elset->parent->right = y;y->right = t;t->parent = y;}//在红黑树中插入新的元素void rbInsert(const Comparable z,int c=RED){RBNode *y = nilNode;RBNode *x = root;//如果是插入的第一个节点，将根节点的值设定为z即可if (currenSize == 0){root->key=z;currenSize++;}else{while (x != nilNode){y = x;if (z < x->key)x = x->left;elsex = x->right;}RBNode *t = new RBNode(y, nilNode, nilNode, z, c);if (z<y->key)y->left = t;elsey->right = t;currenSize++;rbInsertFixup(t);//保持红黑树性质}}void rbInsertFixup(RBNode *t){while (t!=root&&t->parent->color == RED){//如果父节点是祖父节点的左儿子if (t->parent == t->parent->parent->left){//y指向t的叔节点RBNode *y = t->parent->parent->right;//如果叔节点为红色，则将父节点和叔节点变为黑色//同时把祖父节点变为红色，然后指针指向祖父节点以判断祖父节点是否符合性质if (y->color == RED){t->parent->color = BLACK;y->color = BLACK;if (t->parent->parent != root)t->parent->parent->color = RED;t = t->parent->parent;}//如果叔节点为黑色，则需要通过两次旋转//如果当前节点为右子树else if (t == t->parent->right){t = t->parent;leftRotate(t);t->parent->color = BLACK;t->parent->parent->color= RED;rightRotate(t->parent->parent);}//如果当前节点为左子树else{t = t->parent;rightRotate(t);t->parent->color = BLACK;    t->parent->parent->color = RED;rightRotate(t->parent->parent);}}//如果父节点是祖父节点的右儿子else{RBNode *y = t->parent->parent->right;//如果叔节点为红色，则将父节点和叔节点变为黑色//同时把祖父节点变为红色，然后指针指向祖父节点以判断祖父节点是否符合性质if (y->color == RED){t->parent->color = BLACK;y->color = BLACK;if (t->parent->parent!=root)t->parent->parent->color = RED;t = t->parent->parent;}//如果叔节点为黑色，则需要通过两次旋转//如果当前节点为左子树else if (t == t->parent->left){t = t->parent;rightRotate(t);t->parent->color = BLACK;t->parent->parent->color = RED;leftRotate(t->parent->parent);}//如果当前节点为右子树else{t = t->parent;leftRotate(t);t->parent->color = BLACK;t->parent->parent->color = RED;leftRotate(t->parent->parent);}}}}};