本文实例为大家分享了C语言非递归后序遍历二叉树的具体代码，供大家参考，具体内容如下
法一：实现思路：一个栈 先按 根->右子树->左子树的顺序访问二叉树。访问时不输出。另一个栈存入前一个栈只进栈的结点。
最后输出后一个栈的结点数据。
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#include<stdio.h>#include<stdlib.h>typedef struct TreeNode{ char element; struct TreeNode *left,*right;}Tree,*BTree;typedef struct StackNode{ BTree data; struct StackNode *next;}Stack,*PStack;typedef struct{ PStack top; }LinkStack,*PLinkStack;//初始化空栈PLinkStack Init_Stack(void){ PLinkStack S; S=(PLinkStack)malloc(sizeof(LinkStack)); if(S){ S->top=NULL; } return S;}//压栈void Push_Stack(PLinkStack S,BTree T){ PStack p; p=(PStack)malloc(sizeof(Stack)); p->data=T; p->next=S->top; S->top=p;}//判空int empty_Stack(PLinkStack S){ if(S->top){ return 0; }else{ return 1; }}//出栈PStack Pop_Stack(PLinkStack S){ PStack q; if(empty_Stack(S)){ return S->top; }else{ q=S->top; S->top=S->top->next; } return q; }//销毁栈void DestroyStack(PLinkStack S){ PStack del; while(S->top!=NULL){ del=S->top; S->top=S->top->next; free(del); } free(S);} BTree BuildTree(void){ char ch; BTree node; ch=getchar(); if(ch=='#'){ node=NULL; }else{ node=(BTree)malloc(sizeof(Tree)); node->element=ch; node->left=BuildTree(); node->right=BuildTree(); } return node;}void NotRecursionPostOrder(BTree T){ PLinkStack S,CS; S=Init_Stack(); CS=Init_Stack(); while(T || !empty_Stack(S)){ if(T){ Push_Stack(S,T); Push_Stack(CS,T); T=T->right; }else{ T=Pop_Stack(S)->data; T=T->left; } } while(CS->top!=NULL){ printf("%c",CS->top->data->element); CS->top=CS->top->next; } DestroyStack(CS);}int main(void){ BTree T; T=BuildTree(); NotRecursionPostOrder(T); return 0;} |
法二：实现思路。按先序遍历访问每一个结点。存入栈中，当为空时，就出立即栈（第一次出栈）。出栈后应该立即进栈，去访问进栈结点的右结点，这样可以保证先输出左、右结点，再输出根结点。二次进栈利用flag标记。
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#include<stdio.h>#include<stdlib.h>typedef struct TreeNode { char element; int flag; struct TreeNode *left, *right;}Tree, *BTree;typedef struct StackNode { BTree data; struct StackNode *next;}Stack, *PStack;typedef struct { PStack top;}LinkStack, *PLinkStack;//初始化空栈PLinkStack Init_Stack(void) { PLinkStack S = (PLinkStack)malloc(sizeof(LinkStack)); if (S) { S->top = NULL; } return S;}//压栈void Push_Stack(PLinkStack S, BTree T) { PStack p; p = (PStack)malloc(sizeof(Stack)); p->data = T; p->next = S->top; S->top = p;}//判空int empty_Stack(PLinkStack S) { if (S->top) { return 0; } else { return 1; }}//出栈PStack Pop_Stack(PLinkStack S) { PStack q = S->top; S->top = S->top->next; return q;}BTree BuildTree(void) { BTree t; char ch; ch = getchar(); if (ch == '#') { t = NULL; } else { t = (BTree)malloc(sizeof(Tree)); t->element = ch; t->left = BuildTree(); t->right = BuildTree(); } return t;}void DestroyStack(PLinkStack S){ PStack p; while(S->top){ p=S->top; free(p); S->top=S->top->next; }} void NotRecursionPostOrder(BTree T) { PLinkStack S; S = Init_Stack(); while (T || !empty_Stack(S)) { if (T) { T->flag = 0; Push_Stack(S, T); T = T->left; } else { T = Pop_Stack(S)->data; if (T->flag == 0) { T->flag = 1; Push_Stack(S, T); T = T->right; } else { if (T->flag == 1) { printf("%c", T->element); T = NULL; } } } } DestroyStack(S);//销毁栈 }int main(void) { BTree T; T = BuildTree(); NotRecursionPostOrder(T); return 0;} |
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持服务器之家。
原文链接：http://blog.csdn.net/chendongqaq/article/details/70832303
