// 模拟二叉树.cpp : 定义控制台应用程序的入口点。
//

#include "stdafx.h"
#include "stdio.h"
#include "malloc.h"


typedef struct TNode
{
    int data;
    struct TNode *left;
    struct TNode *right;
}Tree;

void Insert(Tree *T,int value)
{

    struct TNode *tmp;
    Tree *t;//有问题
    if(T==NULL)
    {
        tmp=(struct TNode *)malloc(sizeof(TNode));
        tmp->data =value;
        tmp->left =NULL;
        tmp->right=NULL;
        *t=tmp;        
    }
    else
    {
        if(value<=T->data)
        {
            if(T->left!=NULL)
                Insert(&(T->left),value);
            else
            {
                tmp=(struct TNode *)malloc(sizeof(TNode));
                tmp->data =value;
                tmp->left =NULL;
                tmp->right=NULL;
                *t->left=tmp;   
            }
        }
        else
        {
            if(T->right!=NULL)
                Insert(&(T->right),value);
            else
            {
                tmp=(struct TNode *)malloc(sizeof(TNode));
                tmp->data =value;
                tmp->left =NULL;
                tmp->right=NULL;
                *t->right=tmp;   
            }
        }
    }

}

int  PreOrder(Tree T)
{
    if(T==NULL)
        return 0;
    else
    {
        printf("%d\t",T->data );
        PreOrder(T->left);
        PreOrder(T->right);
    }
}


int _tmain(int argc, _TCHAR* argv[])
{
    Tree T;
    int i,a,n;
    T=NULL;
    scanf("%d\n",&n);

    for(i=0;i<n;i++)
    {
        scanf("%d\n",&a);
        Insert(&T,a);        
    }

    PreOrder(T);
    return 0;
}

Tree 不是指针类型

定义一个节点treenode和一个指针tptr

谢谢