数据结构—二叉线索树

原理：参考趣学数据结构

代码：

#include<stdio.h>
#include<stdlib.h>
typedef struct bmTree {int data;struct bmTree* lchild, *rchild;int ltag, rtag;
}bmTree;
bmTree * pre=NULL;//中序遍历的前驱指针
void createBTree(bmTree* & BMTree) {//创建二叉树int data;scanf_s("%d", &data);if (data == -1) {BMTree = NULL;}else {BMTree= (bmTree*)malloc(sizeof(bmTree));BMTree->data = data;createBTree(BMTree->lchild);createBTree(BMTree->rchild);}}
void midTraverseBMTree(bmTree* & BMTree) {//中序构造二叉线索树bmTree* T = BMTree;if (T) {midTraverseBMTree(T->lchild);if (!T->lchild) {T->ltag = 1;//指向直接前驱T->lchild = pre;}else {T->ltag = 0;//有左孩子}if (pre) {if (!pre->rchild) {pre->rtag = 1;//直接后继pre->rchild = T;}else {pre->rtag = 0;//有右孩子}}pre = T;midTraverseBMTree(T->rchild);}
}
void printMideBMT(bmTree * T) {//遍历二叉线索树bmTree *p = T;while (p) {while (p->ltag==0) {p = p->lchild;}printf("%d ", p->data);//左结点while (p->rtag == 1&&p->rchild) {p = p->rchild;printf("%d ", p->data);//根|右结点}p = p->rchild;//右子树}
}
int main() {bmTree* T;createBTree(T);midTraverseBMTree(T);pre->rchild = NULL;//中序遍历的最后一个元素，没有后继pre->rtag = 1;printf("二叉线索树进行中序遍历:");printMideBMT(T);printf("\n");system("pause");return 0;
}

测试截图：

时间复杂度O(nlogn),空间复杂度O(1)

如果存在什么问题，欢迎批评指正！谢谢！