二叉树的生成和遍历

  源文件

#include"define.h"

int main()
{
	bitree *root=create();
	printf("二叉树的先序遍历：\n");
	preorder(root);printf("\n");
	printf("中序遍历:\n");
	inorder(root);printf("\n");
	printf("后序遍历\n");
	postorder(root);printf("\n");

	return 0;
}

头文件

#include<stdio.h>
#include<malloc.h>
#define MAXSIZE 1024

typedef char datatype;
typedef struct lnode{
	datatype data;
	struct lnode *lchild,*rchild;
} bitree;

//生成二叉树
bitree *create()
{
	bitree *root,*s,*Q[MAXSIZE];
	datatype x;
	unsigned int front=1,rear=0;
	scanf("%c",&x);
	while(x!='#')
	{
		if(x!='@')
		{
			s=(bitree *)malloc(sizeof(bitree));
			s->data=x;
			s->lchild=NULL;
			s->rchild=NULL;
		}
		rear++;
		Q[rear]=s;
		if(rear==1)	root=s;
		else
		{
			if(rear%2)	Q[front]->rchild=s;
			else		Q[front]->lchild=s;	
			if(rear%2)	front++;
		}
		
		scanf("%c",&x);
	}


	return root;
}

void preorder(bitree *root)
{
	bitree *t=root;
	if(t)
	{
		printf("%c,",t->data);
		preorder(t->lchild);
		preorder(t->rchild);
	}
}

//中序遍历
void inorder(bitree *root)
{
	bitree *t=root;
	if(t)
	{
		inorder(t->lchild);
		printf("%c,",t->data);
		inorder(t->rchild);
	}
}

//后序遍历
void postorder(bitree *root)
{
	bitree *t=root;
	if(t)
	{
		postorder(t->lchild);
		postorder(t->rchild);
		printf("%c,",t->data);
	}
}