A non-recursive algorithm for sequential traversal of binary tree (C language)

First of all, thank you for the ' Hicjiajia ' blog post: two fork tree sequential traversal (non-recursive)

This essay opens up my blogging process and becomes a member of thousands of programmers, and insists on going farther!

Tortured me for the afternoon of the post-order traverse Noon to be resolved, the key is to mark the right subtree is visited, consider modifying the binary tree node data structure, add a visit domain, or build a stack to store the visited node. are more troublesome without debugging success. If the right subtree is also in the stack, if there is no access to the tag, it will change the order of access, or even a dead loop, this is a more dangerous situation. From the reference blog, excerpt and rewrite the code as C, basically no changes. Follow the questions and try to write your own original code.

Binary tree stores the data type int, with the number 0 indicating that the subtree is empty

Input: 1 2 3 0 8 0 0 4 0 0 5 6 0 0 7 0 0

Get post-post traversal results: 83426751

1#include <stdio.h>2#include <stdlib.h>3 4 #defineOK 15 #defineERROR 06 #defineMaxSize 1007 8typedefintElemtype;9typedefintStatus;Ten  Onetypedefstructbtnode{ A elemtype data; -     structBtnode *lchild,*Rchild; - }btree; the  -typedefstructst{ -     structbtnode*Data[maxsize]; -     inttop; + }stack;  - //1. Generate two fork trees in order of precedence +btree*Createt () { ABTree *BT; at Elemtype ch; -scanf"%d",&ch); -     if(ch==0) -bt=NULL; -     Else{ -bt= (btree*) malloc (sizeof(BTree)); in         if(!BT)        {exit (OVERFLOW);}  -Bt->data=ch; toBt->lchild=createt (); +Bt->rchild=createt (); -     } the     returnBT; * }  $ Panax Notoginseng //4. Post-Traversal -Status Postorder (BTree *BT) { the     if(BT) { +Postorder (bt->lchild); APostorder (bt->rchild); theprintf"%3d",bt->data); +         returnOK; -     } $     Else returnERROR; $ } - //4. Post-traversal-non-recursive -Status PostOrder2 (BTree *BT) { the Stack s,s2; -BTree *T;Wuyi     intFlag[maxsize]; thes.top=0; -t=BT; Wu      while(s.top!=0||T) { -          while(T) About         { $s.data[s.top++]=T; -flag[s.top-1]=0; -T=t->Lchild; -          }  A           while(s.top!=0&&flag[s.top-1]==1){ +t=s.data[--S.top]; theprintf"%3d",t->data); -          } $          if(s.top!=0){ theflag[s.top-1]=1; thet=s.data[s.top-1]; theT=t->Rchild; the          } -          Else    Break; in     } the     returnOK; the } About intMain () { theBTree *BT; thebt=createt (); the     if(Postorder (BT)) { +printf"\ nthe post-traversal is complete! \ n"); -     }     the     if(PostOrder2 (BT)) {Bayiprintf"\ n Non-recursive post-traversal completion! \ n"); the     } the}

A non-recursive algorithm for sequential traversal of binary tree (C language)