二叉树遍历，递归和非递归方法

来源：互联网发布：聊天软件默默编辑：程序博客网时间：2024/05/19 16:37
// BinTree.cpp : 定义控制台应用程序的入口点。//#include "stdafx.h"#include <windows.h>#include <tchar.h> #include <stdio.h>#include <string>#include <stack>using namespace std;typedef struct BinTree{BinTree* lChild;BinTree* rChild;string strValue;}BinTree;void preOrder(BinTree* root);void preOrderNoneRecursion(BinTree* root);void inOrder(BinTree* root);void inOrderrNoneRecursion(BinTree* root);void postOrder(BinTree* root);void postOrderNoneRecursion(BinTree* root);BinTree* formTestBinTree();int _tmain(int argc, _TCHAR* argv[]){BinTree* root = formTestBinTree();printf("preOrder recursion:");preOrder(root);printf("\n");printf("preOrder none recursion:");preOrderNoneRecursion(root);printf("\n");printf("inOrder recursion:");inOrder(root);printf("\n");printf("inOrder none recursion:");inOrderrNoneRecursion(root);printf("\n");printf("postOrder recursion:");postOrder(root);printf("\n");printf("postOrder none recursion:");postOrderNoneRecursion(root);printf("\n");return 0;}BinTree* formTestBinTree(){//layer3BinTree* layer3_1 = new BinTree();layer3_1->strValue = 'D';layer3_1->lChild = NULL;layer3_1->rChild = NULL;BinTree* layer3_2 = new BinTree();layer3_2->strValue = 'E';layer3_2->lChild = NULL;layer3_2->rChild = NULL;BinTree* layer3_3 = new BinTree();layer3_3->strValue = 'F';layer3_3->lChild = NULL;layer3_3->rChild = NULL;//layer2BinTree* layer2_1 = new BinTree();layer2_1->strValue = 'B';layer2_1->lChild = layer3_1;layer2_1->rChild = layer3_2;BinTree* layer2_2 = new BinTree();layer2_2->strValue = 'C';layer2_2->lChild = layer3_3;layer2_2->rChild = NULL;BinTree* root = new BinTree();root->strValue = 'A';root->lChild = layer2_1;root->rChild = layer2_2;return root;}void preOrder(BinTree* root){if(!root){return;}//_tprintf(TEXT("%s"), root->strValue);printf("%s", root->strValue.c_str());preOrder(root->lChild);preOrder(root->rChild);}void preOrderNoneRecursion(BinTree* root){stack<BinTree*> s;BinTree *p=root;while(p!=NULL||!s.empty()){while(p!=NULL){printf("%s", p->strValue.c_str());s.push(p);p=p->lChild;}if(!s.empty()){p=s.top();s.pop();p=p->rChild;}}}void inOrder(BinTree* root){if(!root){return;}inOrder(root->lChild);printf("%s", root->strValue.c_str());inOrder(root->rChild);}void inOrderrNoneRecursion(BinTree* root){stack<BinTree*> s;BinTree *p=root;while(p!=NULL||!s.empty()){while(p!=NULL){s.push(p);p=p->lChild;}if(!s.empty()){p=s.top();printf("%s", p->strValue.c_str());s.pop();p=p->rChild;}}    }void postOrder(BinTree* root){if(!root){return;}postOrder(root->lChild);postOrder(root->rChild);printf("%s", root->strValue.c_str());}void postOrderNoneRecursion(BinTree* root){stack<BinTree*> s;BinTree *cur;                      //当前结点 BinTree *pre=NULL;                 //前一次访问的结点 s.push(root);while(!s.empty()){cur=s.top();if((cur->lChild==NULL && cur->rChild==NULL)|| (pre!=NULL && (pre==cur->lChild||pre==cur->rChild))){printf("%s", cur->strValue.c_str());  //如果当前结点没有孩子结点或者孩子节点都已被访问过 s.pop();pre=cur; }else{if(cur->rChild != NULL)s.push(cur->rChild);if(cur->lChild != NULL)    s.push(cur->lChild);}}    }
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