本文實例為大家分享了C語言非遞歸后序遍歷二叉樹的具體代碼，供大家參考，具體內容如下
法一：實現思路：一個棧 先按 根->右子樹->左子樹的順序訪問二叉樹。訪問時不輸出。另一個棧存入前一個棧只進棧的結點。
最后輸出后一個棧的結點數據。
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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;//初始化空棧PLinkStack Init_Stack(void){ PLinkStack S; S=(PLinkStack)malloc(sizeof(LinkStack)); if(S){ S->top=NULL; } return S;}//壓棧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; }}//出棧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; }//銷毀棧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：實現思路。按先序遍歷訪問每一個結點。存入棧中，當為空時，就出立即棧（第一次出棧）。出棧后應該立即進棧，去訪問進棧結點的右結點，這樣可以保證先輸出左、右結點，再輸出根結點。二次進棧利用flag標記。
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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;//初始化空棧PLinkStack Init_Stack(void) { PLinkStack S = (PLinkStack)malloc(sizeof(LinkStack)); if (S) { S->top = NULL; } return S;}//壓棧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; }}//出棧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);//銷毀棧 }int main(void) { BTree T; T = BuildTree(); NotRecursionPostOrder(T); return 0;} |
以上就是本文的全部內容，希望對大家的學習有所幫助，也希望大家多多支持服務器之家。
原文鏈接：http://blog.csdn.net/chendongqaq/article/details/70832303
