红黑树

理论知识参见 《数据结构基础 》 张力译版

以下代码与大家分享，如有错误之处希望批评指正。（我已测试通过）

//RedBlackTree.h#ifndef _REDBLACKTREE_#define _REDBLACKTREE_class TreeNode{friend class RedBlackTree;public:TreeNode(int e){key=e;rb=0;leftchild=rightchild=0;}private:int key;bool rb;//颜色标记0 红 1 blackTreeNode *leftchild, *rightchild;};class RedBlackTree{public:RedBlackTree(TreeNode* init=0){root=0;}void Insert(const int e);private:TreeNode * root;};#endif

//RedBlackTree.cpp#include "RedBlackTree.h"#include <iostream>#include <stack>using namespace std;void RedBlackTree::Insert(const int e){if (!root){root=new TreeNode(e);root->rb=1;//根节点始终是黑色return ;}stack<TreeNode*>s;//记录遍历路径TreeNode *u=root;TreeNode *pu=0;//u的父节点TreeNode *gu=0;//u的祖父节点TreeNode *uu=0;//叔父节点while(u)//查找插入位置{s.push(u);/*关键字查找*/if (e==u->key)//已有该关键字 {return;}else if (e<u->key){u=u->leftchild;}else {u=u->rightchild;}}bool inflag=0; //新节点尚未插入u=new TreeNode(e);pu=s.top();//得到父节点s.pop();while (1)//一直进行{if (s.empty())//s空 仅有父节点 {//无祖父节点if (!inflag)// 尚未插入{if (e<pu->key){pu->leftchild=u;}else if (e>pu->key){pu->rightchild=u;}inflag=1;}return ;}else{gu=s.top();s.pop();//尚未插入则插入if (!inflag)// 尚未插入{if (e<pu->key){pu->leftchild=u;}else if (e>pu->key){pu->rightchild=u;}inflag=1;}//判断当前的u是否违反性质2  不违反则返回，违反则分类操作if (pu->rb!=u->rb)//不违反性质2{return;}else{//分类 r bif (pu==gu->leftchild){uu=gu->rightchild;} else{uu=gu->leftchild;}if (uu&&uu->rb==0)//red 颜色变换   LL 与RL 变换相同{if (gu->leftchild==pu)//1L{//if (pu->leftchild==u)//2L  (LL)//{//LLr  颜色变换gu->rb=0;uu->rb=1;pu->rb=1;//}//else//2R (LR)//{//gu->rb=0;//uu->rb=1;//pu->rb=1;//}} else//1R{//if (pu->leftchild==u)//2L  (RL)//{//RLr  颜色变换gu->rb=0;uu->rb=1;pu->rb=1;//}//else//2R (RR)//{//gu->rb=0;//uu->rb=1;//pu->rb=1;//}}u=gu;//准备下次判断、操作if (!s.empty()){pu=s.top();s.pop();}else{u->rb=1;//root}}else// b 旋转{if (gu->leftchild==pu)//1L{if (pu->leftchild==u)//2L  (LL){//LLb  旋转gu->leftchild=pu->rightchild;pu->rightchild=gu;pu->rb=1;gu->rb=0;}else//2R (LRb){gu->leftchild=u->rightchild;pu->rightchild=u->leftchild;u->leftchild=pu;u->rightchild=gu;u->rb=1;gu->rb=0;pu->rb=0;}} else//1R{if (pu->leftchild==u)//2L  (RL){//RLb  旋转pu->leftchild=u->rightchild;gu->rightchild=u->leftchild;u->rightchild=pu;u->leftchild=gu;u->rb=1;gu->rb=0;pu->rb=0;}else//2R (RR){gu->rightchild=pu->leftchild;pu->leftchild=gu;pu->rb=1;gu->rb=0;}}if (!s.empty()){pu=s.top();s.pop();}else{root=u;u->rb=1;//rootreturn;}if (e<pu->key){pu->leftchild=u;}else{pu->rightchild=u;}return;}}}}}

//main.cpp#include <iostream>#include "RedBlackTree.h"using namespace std;void main(){RedBlackTree rbt;rbt.Insert(50);rbt.Insert(10);rbt.Insert(80);    rbt.Insert(90);rbt.Insert(70);rbt.Insert(60);rbt.Insert(65);rbt.Insert(62);}