程序员面试100题(算法)之把二叉查找树转变成排序的双向链表(含二叉树前序创建、递归)

// Test2.cpp : 定义控制台应用程序的入口点。//程序员面试100题(算法)之把二叉查找树转变成排序的双向链表#include "stdafx.h"#include<iostream>#include<vector>using namespace std;struct BSTreeNode{BSTreeNode *leftNode;BSTreeNode *rightNode;int value;};BSTreeNode* createBiTree(BSTreeNode *&tNode){int value = 0;cin >> value;if(value == -1){tNode = NULL;}else{tNode = (BSTreeNode*)malloc(sizeof(BSTreeNode));if(!tNode){cout << "Out of space!" << endl;return NULL;}else{tNode->value = value;createBiTree(tNode->leftNode);createBiTree(tNode->rightNode);}}return tNode;}void convertBSTreeToLinklist(BSTreeNode *node, BSTreeNode *&tailOfLinklist){if(!node){return;}BSTreeNode *currentNode = node;if(currentNode->leftNode){convertBSTreeToLinklist(currentNode->leftNode, tailOfLinklist);}currentNode->leftNode = tailOfLinklist;if(tailOfLinklist)tailOfLinklist->rightNode = currentNode;tailOfLinklist = currentNode;if(currentNode->rightNode){convertBSTreeToLinklist(currentNode->rightNode, tailOfLinklist);}}BSTreeNode *convertSolution(BSTreeNode *root){BSTreeNode *tailOfLinklist = NULL;convertBSTreeToLinklist(root, tailOfLinklist);while(tailOfLinklist->leftNode){tailOfLinklist = tailOfLinklist->leftNode;}return tailOfLinklist;}void printLinklist(BSTreeNode *head){if(head){while(head){cout << head->value << "\t";head = head->rightNode;}cout << endl;}else{cout << "The double link list is empty" << endl;}}int _tmain(int argc, _TCHAR* argv[]){BSTreeNode* bTree = NULL;BSTreeNode* headOfLinklist = NULL;cout << "Create the BSTree with preorder:" <<endl;cout << "Please enter the integer, -1 means node is empty." <<endl;bTree = createBiTree(bTree);cout << "Starting convert the BSTree to double link list" <<endl;headOfLinklist = convertSolution(bTree);cout << "Print the double link list" <<endl;printLinklist(headOfLinklist);return 0;}