二叉树的层次建树（辅助队列）以及结点的遍历函数实现

二叉树构建与遍历

最新推荐文章于 2022-12-11 17:08:13 发布

原创最新推荐文章于 2022-12-11 17:08:13 发布 · 409 阅读

0 ·

CC 4.0 BY-SA版权

数据结构与算法学习笔记专栏收录该内容

18 篇文章

订阅专栏

本文详细介绍了如何使用C语言构建二叉树，并实现前序、中序和后序遍历。通过定义节点结构体，创建队列来辅助树的构建过程，实现了从输入字符构建二叉树的功能。最后，通过三种不同的遍历方式展示了树的结构。

BinaryTree.h头文件

#pragma once
#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
typedef char ElemType;   
typedef struct node 
{
	char c; 
	struct node* left; 
	struct node* right;  
}Node,*pNode;
typedef struct quene 
{
	pNode InsertPos;
	struct quene* next;
}Quene, *pQuene;
void preOrder(pNode p);
void midOrder(pNode p);
void latOrder(pNode p);
void buildBinaryTree(pNode* treeRoot, pQuene* queHead, pQuene* queTail, ElemType value);
void clearQuene(pQuene* queHead);

BinaryTree.c文件

#include "BinaryTree.h"

void preOrder(pNode p)
{
	if (p != NULL)
	{
		putchar(p->c);
		preOrder(p->left);
		preOrder(p->right);
	}
}
void midOrder(pNode p)
{
	if (p != NULL)
	{
		midOrder(p->left);
		putchar(p->c);
		midOrder(p->right);
	}
}
void latOrder(pNode p)
{
	if (p != NULL)
	{
		latOrder(p->left);
		latOrder(p->right);
		putchar(p->c);
	}
}
void buildBinaryTree(pNode* treeRoot, pQuene* queHead, pQuene* queTail, ElemType value)
{
	pNode treeNew = (pNode)calloc(1, sizeof(Node));
	pQuene queNew = (pQuene)calloc(1, sizeof(Quene));
	pQuene queCur = *queHead;
	treeNew->c = value;
	queNew->InsertPos = treeNew;
	if (NULL == *treeRoot)
	{
		*treeRoot = treeNew;
		*queHead = queNew;
		*queTail = queNew;
	}
	else {
		(*queTail)->next = queNew;
		*queTail = queNew;
		if (NULL == queCur->InsertPos->left)
		{
			queCur->InsertPos->left = treeNew;
		}
		else if (NULL == queCur->InsertPos->right)
		{
			queCur->InsertPos->right = treeNew;
			*queHead = queCur->next;
			free(queCur);
			queCur = NULL;
		}
	}
}
void clearQuene(pQuene* queHead)
{
	pQuene queCur;
	while (*queHead)
	{
		queCur = *queHead;
		*queHead = queCur->next;
		free(queCur);
	}
}

main.c文件

#include "BinaryTree.h"

int main()
{
	ElemType val;
	pNode treeRoot = NULL;
	pQuene queHead = NULL, queTail = NULL;
	while (scanf("%c", &val) != EOF)
	{
		if (val == '\n')
		{
			break;
		}
		buildBinaryTree(&treeRoot, &queHead, &queTail, val);
	}
	clearQuene(&queHead);
	preOrder(treeRoot);
	printf("\n-----------------------\n");
	midOrder(treeRoot);
	printf("\n-----------------------\n");
	latOrder(treeRoot);
	return 0;
}