之前看过的前序遍历的线索二叉树感觉写的有点问题这里更新一下我的思路

前序线索化

#include<iostream>
using namespace std;typedef int datatype;
typedef struct BitNode
{datatype Data;struct BitNode* leftchild;struct BitNode* rightchild;int lefttag;int righttag;
}Node;
#pragma region 前序线索化递归遍历
Node* previous = NULL;
void PreCuleOrder(Node* root)
{if (root == NULL){return;}Node* tmpnode = NULL;tmpnode = root;if (tmpnode->leftchild == NULL ){tmpnode->leftchild = previous;tmpnode->lefttag = 1;}if (previous != NULL && previous->rightchild == NULL){previous->rightchild = tmpnode;previous->righttag = 1;}previous = tmpnode;if (tmpnode->lefttag ==0){PreCuleOrder(tmpnode->leftchild);}if (tmpnode->righttag == 0){PreCuleOrder(tmpnode->rightchild);}
}
#pragma endregion

前序线索化遍历

#pragma region 前序遍历线索化二叉树
void PreIterativeTree(Node* root)
{if (root == NULL){return;}Node* tmpnode = NULL;tmpnode = root;while (tmpnode!=NULL){/*如果左子树一直非存在前继结点 那么一直遍历*/while (tmpnode->lefttag ==0){	cout << tmpnode->Data << endl;tmpnode = tmpnode->leftchild;}/*出现连接上一层前继结点的叶子结点*/while (tmpnode->rightchild !=NULL){if (tmpnode->lefttag ==0){break;}else{cout << tmpnode->Data << endl;tmpnode = tmpnode->rightchild;}}if (tmpnode->rightchild == NULL){cout << tmpnode->Data << endl;break;}}
}
#pragma endregion

主函数代码

int main(void)
{BitNode* n1 = new BitNode();BitNode* n2 =  new BitNode();BitNode* n3 =  new BitNode();BitNode* n4 =  new BitNode();BitNode* n5 =  new BitNode();BitNode* n6 =  new BitNode();BitNode* n7 =  new BitNode();BitNode* n8 =  new BitNode();BitNode* n9 =  new BitNode();n1->Data = 1, n2->Data = 2, n3->Data = 3, n4->Data = 4, n5->Data = 5, n6->Data = 6, n7->Data = 7, n8->Data = 8, n9->Data = 9;n1->leftchild = n2;n1->lefttag = 0;n2->leftchild = n4;n2->lefttag = 0;n4->leftchild = n5;n4->lefttag = 0;n1->rightchild = n3;n1->righttag = 0;n3->rightchild = n7;n3->righttag = 0;n3->leftchild = n6;n3->lefttag = 0;n7->leftchild = n9;n7->lefttag = 0;n7->rightchild = n8;n7->righttag = 0;PreCuleOrder(n1);PreIterativeTree(n1);return 0;
}