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头文件——————————————————————————————#ifndef _BINARY_SEARCH_TREE_H_#define _BINARY_SEARCH_TREE_H_#include <stdlib.h>#include <iomanip>#include <iostream>#include <stack>#include <set>#define Element intstruct TreeNode{ Element data; struct TreeNode *left; struct TreeNode *right;};typedef struct TreeNode *Position;typedef Position BinarySearchTree;void MakeEmpty(BinarySearchTree* pbst);Position Find(Element x, BinarySearchTree bst);Position FindMin(BinarySearchTree bst);Position FindMax(BinarySearchTree bst);void Insert(Element x, BinarySearchTree* pbst);void Delete(Element x, BinarySearchTree* pbst);Element Retrieve(Position p);void PrintTree(BinarySearchTree bst, int Depth, int ctrl);void PreOrder(BinarySearchTree bst);void InOrder(BinarySearchTree bst);void PostOrder(BinarySearchTree bst);void PreOrderNotRecursion(BinarySearchTree bst);void InOrderNotRecursion(BinarySearchTree bst);void PostOrderNotRecursion(BinarySearchTree bst);#endif源文件——————————————————————————————#include "BinarySearchTree.h"void MakeEmpty(BinarySearchTree* pbst){ if(NULL != (*pbst)) { MakeEmpty(&((*pbst)->left)); MakeEmpty(&((*pbst)->right)); free(*pbst); *pbst = NULL; } return ;}Position Find(Element x, BinarySearchTree bst){ while(NULL != bst) { if(x < Retrieve(bst)) bst = bst->left; else if(x > Retrieve(bst)) bst = bst->right; else break; } return bst;}Position FindMin(BinarySearchTree bst){ while(NULL != bst && NULL != bst->left) bst = bst->left; return bst;}Position FindMax(BinarySearchTree bst){ while(NULL != bst && NULL != bst->right) bst = bst->right; return bst;}void Insert(Element x, BinarySearchTree* pbst){ if(NULL == *pbst) { Position tmp = (Position)malloc(sizeof(struct TreeNode)); if(NULL == tmp) return ; tmp->data = x; tmp->left = tmp->right = NULL; *pbst = tmp; } else if(x < (*pbst)->data) Insert(x, &((*pbst)->left)); else if(x > (*pbst)->data) Insert(x, &((*pbst)->right)); else return ;}void Delete(Element x, BinarySearchTree* pbst){ if(NULL == *pbst) return ; if(x < (*pbst)->data)//go left Delete(x, &((*pbst)->left)); else if(x > (*pbst)->data)//go right Delete(x, &((*pbst)->right)); else //the x is found, the *pbst points to the x { if(NULL != (*pbst)->left && NULL != (*pbst)->right)//the x has two children { Position tmp = FindMin((*pbst)->right); (*pbst)->data = tmp->data; Delete((*pbst)->data, &((*pbst)->right)); } else //the x has one or none child { Position tmp = (*pbst); if(NULL != (*pbst)->left) //the x has left child (*pbst) = tmp->left; else if(NULL != (*pbst)->right) //the x has right child (*pbst) = tmp->right; else //the x has none child (*pbst) = NULL; free(tmp); } }}Element Retrieve(Position p){ return p->data;}void PrintTree(BinarySearchTree bst, int Depth, int ctrl)//ctrl:0=root 1=left 2=right{ if(NULL != bst) { std::cout<<std::setw(Depth); if(0 == ctrl) std::cout<<"rt:"; else if(1 == ctrl) std::cout<<"l"; else if(2 == ctrl) std::cout<<"r"; std::cout<<bst->data<<std::endl; PrintTree(bst->left, Depth+3, 1); PrintTree(bst->right, Depth+3, 2); }}void PreOrder(BinarySearchTree bst){ if(NULL != bst) { std::cout<<bst->data<<"-"; PreOrder(bst->left); PreOrder(bst->right); }}void InOrder(BinarySearchTree bst){ if(NULL != bst) { InOrder(bst->left); std::cout<<bst->data<<"-"; InOrder(bst->right); }}void PostOrder(BinarySearchTree bst){ if(NULL != bst) { PostOrder(bst->left); PostOrder(bst->right); std::cout<<bst->data<<"-"; }}void InOrderNotRecursion(BinarySearchTree bst)//二叉查找数的非递归版中序遍历，利用栈来模拟函数递归调用{ std::stack<Position> s; while(NULL != bst)//沿着最左的方向将左儿子依次压入栈中 { s.push(bst); bst = bst->left; } while(!s.empty()) { Position pos = s.top(); s.pop(); std::cout<<pos->data<<"-"; if(NULL != pos->right)//pos has right child { pos = pos->right; while(NULL != pos)//沿着最左的方向将左儿子依次压入栈中 { s.push(pos); pos = pos->left; } } }}void PreOrderNotRecursion(BinarySearchTree bst)//二叉查找数的非递归版先序遍历{ std::stack<Position> s; s.push(bst); while(!s.empty()) { Position pos = s.top(); s.pop(); std::cout<<pos->data<<"-"; if(NULL != pos->right)//如果pos有右儿子就先将其右儿子压入栈中 s.push(pos->right); if(NULL != pos->left)//如果pos有左儿子就再将其左儿子压入栈中 s.push(pos->left); }}void PostOrderNotRecursion(BinarySearchTree bst)//二叉查找数的非递归版后序遍历{ std::stack<Position> s; std::set<Position> rchild_visited; while(NULL != bst)//沿着最左的方向将左儿子依次压入栈中 { s.push(bst); bst = bst->left; } while(!s.empty()) { Position pos = s.top(); //s.pop(); if(NULL == pos->right)//pos没有右儿子因此可以直接访问pos { std::cout<<pos->data<<"-"; s.pop(); } else if(rchild_visited.find(pos) == rchild_visited.end()) {//pos有右儿子我们不可以访问pos，需要先访问完其右子树后才可访问pos //因此要进入其右儿子中递归访问右子树同时标记pos的右儿子已经被我们访问过了 rchild_visited.insert(pos); pos = pos->right; while(NULL != pos)//把右子树的根连同其左儿子沿着左儿子的方向依次压入栈中 { s.push(pos); pos = pos->left; } } else if(rchild_visited.find(pos) != rchild_visited.end()) {//此时pos右儿子已经被访问过了因此我们可以直接访问pos了 std::cout<<pos->data<<"-"; rchild_visited.erase(pos); s.pop(); } }} |