(C语言)二叉树非递归遍历前序和中序(数据结构十四)
1.数据类型定义
在代码中为了清楚的表示一些错误和函数运行状态,我们预先定义一些变量来表示这些状态。在head.h头文件中有如下定义:
//定义数据结构中要用到的一些变量和类型 #ifndef HEAD_H #define HEAD_H #include <stdio.h> #include <malloc.h> #include <stdlib.h> #include <math.h> #define TRUE 1 #define FALSE 0 #define OK 1 #define ERROR 0 #define INFEASIBLE -1 #define OVERFLOW -2 //分配内存出错 typedef int Status; //函数返回值类型 typedef int ElemType; //用户定义的数据类型 #endif
2.遍历过程中用到的栈结构代码如下
LinearStack.h中
#ifndef LINEAR_STACK #define LINEAR_STACK #include "head.h" #define STACK_INIT_SIZE 100 #define STACK_INCREMENT 10 typedef pBiNode Type; typedef struct Stack{ Type *base; //栈底 Type *top; //栈顶 int size; //栈大小 }Stack,*pStack; //初始化栈 Status InitStack(pStack &S){ S=(pStack)malloc(sizeof(Stack)); Type* p=(Type*)malloc(STACK_INIT_SIZE*sizeof(Type)); if(!p) return OVERFLOW; S->base=p; S->top=p; S->size=STACK_INIT_SIZE; return OK; } Status freeStack(pStack &S){ free(S); S=NULL; return OK; } //销毁栈 Status DestroyStack(pStack &S){ free(S->base); S->base=NULL; S->top=NULL; freeStack(S); return OK; } //清空栈 Status ClearStack(pStack &S){ S->top=S->base; return OK; } //栈是否为空 Status StackEmpty(pStack S){ return S->top==S->base; } //栈长度 int StackLength(pStack S){ return S->top-S->base; } //得到栈顶数据级e Status GetTop(pStack S,Type &e){ e=*(S->top-1); return OK; } //入栈 Status Push(pStack &S,Type e){ if(StackLength(S)>=S->size) S->base=(Type*)realloc(S->base,(S->size+STACK_INCREMENT)*sizeof(Type)); if(!S->base) return OVERFLOW; S->top=S->base+StackLength(S); S->size+=STACK_INCREMENT; *S->top++=e; return OK; } //出栈 Status Pop(pStack &S,Type &e){ if(StackLength(S)<1) return ERROR; e=*--S->top; return OK; } // Status print(Type e){ // printf("%d ",e); // return OK; // } //用vistit遍历栈 Status StackTraverse(pStack S,Status(*visit)(Type)){ while (S->top>S->base) (*visit)(*--S->top); return OK; } // Status printStack(pStack S){ // StackTraverse(S,print); // return OK; // } #endif3.二叉树结构代码如下
#ifndef BITREE_H #define BITREE_H #include "head.h" typedef struct BiNode{ ElemType data; struct BiNode *left,*right; }BiNode,*pBiNode; Status InsertRight(pBiNode &root,ElemType e); Status InsertLeft(pBiNode &root,ElemType e); Status InitBiTree(pBiNode &tree){ tree=(pBiNode)malloc(sizeof(BiNode)); if(!tree) return OVERFLOW; tree->data=-999999; tree->left=NULL; tree->right=NULL; return OK; } Status BiTreeEmpty(pBiNode root){ if(root==NULL) return ERROR; return root->left==root->right && root->data==-999999; } Status HasNoNode(pBiNode root){ if(root==NULL) return ERROR; return root->left==root->right ; } Status CreatTreeNode(pBiNode &node,ElemType e){ node=(pBiNode)malloc(sizeof(BiNode)); if(!node) return OVERFLOW; node->data=e; node->left=NULL; node->right=NULL; return OK; } Status InsertRight(pBiNode &root,ElemType e){ if(root->right==NULL){ if(e>root->data){ pBiNode p; CreatTreeNode(p,e); root->right=p; return OK; }else{ pBiNode p; CreatTreeNode(p,e); root->left=p; return OK; } }else{ e>root->data? InsertRight(root->right,e):InsertLeft(root,e); } } Status InsertLeft(pBiNode &root,ElemType e){ if(root->left==NULL){ if(e>root->data){ pBiNode p; CreatTreeNode(p,e); root->right=p; return OK; }else{ pBiNode p; CreatTreeNode(p,e); root->left=p; return OK; } }else{ e<=root->data?InsertLeft(root->left,e):InsertRight(root,e); } } Status InsertTree(pBiNode &root,ElemType e){ if(BiTreeEmpty(root)){ root->data=e; return true; } if(e>root->data){ InsertRight(root,e); }else{ InsertLeft(root,e); } } Status CreateBiTree(pBiNode &root,ElemType *a,int n){ for (int i=0;i<n;i++) { InsertTree(root,a[i]); } return true; } Status print(ElemType e ){ printf("%d ",e); return true; } Status PreOrderTraverse(pBiNode root,Status(*p)(int)){ if(root){ (*p)(root->data); PreOrderTraverse(root->left,p); PreOrderTraverse(root->right,p); } return OK; } Status MiddleOrderTraverse(pBiNode root,Status(*p)(int)){ if(root){ MiddleOrderTraverse(root->left,p); (*p)(root->data); MiddleOrderTraverse(root->right,p); } return OK; } Status AfterOrderTraverse(pBiNode root,Status(*p)(int)){ if(root){ AfterOrderTraverse(root->left,p); AfterOrderTraverse(root->right,p); (*p)(root->data); } return OK; } Status ClearBiTree(pBiNode &root){ if(root){ ClearBiTree(root->left); ClearBiTree(root->right); free(root); root==NULL; } return OK; } #endif
4.遍历测试如下
#include "BiTree.h" #include "LinearStack.h" //非递归中序 void MiddleTraverse(pBiNode Root){ pStack S; InitStack(S); pBiNode p=Root; while(p||!StackEmpty(S)){ if(p){ Push(S,p); p=p->left; }else{ Pop(S,p); printf("%d ",p->data); p=p->right; } } } //非递归前序 void PerTraverse(pBiNode Root){ pStack S; InitStack(S); pBiNode p=Root; while(p||!StackEmpty(S)){ if(p){ printf("%d ",p->data); Push(S,p); p=p->left; }else{ Pop(S,p); p=p->right; } } } void main(){ ElemType a[14]={100,50,200,40,30,45,60,55,61,200,150,300,250,400}; pBiNode root; InitBiTree(root); CreateBiTree(root,a,14); printf("前序:"); PreOrderTraverse(root,print); printf("\n中序:"); MiddleOrderTraverse(root,print); printf("\n后序:"); AfterOrderTraverse(root,print); printf("\n非递归前序:"); PerTraverse(root); printf("\n非递归中序:"); MiddleTraverse(root); ClearBiTree(root); }
5.插入的二叉树
前序:100 50 40 30 45 60 55 61 200 150 300 250 400 中序:30 40 45 50 55 60 61 100 150 200 250 300 400 后序:30 45 40 55 61 60 50 150 250 400 300 200 100 非递归前序:100 50 40 30 45 60 55 61 200 150 300 250 400 非递归中序:30 40 45 50 55 60 61 100 150 200 250 300 400