用数组建立二叉树运行出错，不知道哪里错了

感觉逻辑没问题，就是不知道哪里错了，各位帮帮忙，看了好几天了~~~

 #include <iostream>
using namespace std;
#include <stdlib.h>
#define NULLVALUE 0

typedef int Elemtype;

typedef struct Tree{
    Elemtype data;
    struct Tree *LTree;
    struct Tree *RTree;
};

void Create(Tree *tree,Elemtype *data,int &start,int len){
    if(start>=len||data[start]==NULLVALUE){
        return ;
    }
    else{
        tree=(Tree *)malloc(sizeof(Tree));
        tree->data=data[start];
        ++start;
        Create(tree->LTree,data,start,len);
        ++start;
        Create(tree->RTree,data,start,len);
    }
}

void Print(Tree *tree){
    if(tree==NULL)
        return ;
    cout<<tree->data<<"  ";
    Print(tree->LTree);
    Print(tree->RTree);
}

int main(){
    Elemtype data[]={1,2,4,0,0,5,0,0,3,6,0,0,7};
    int len=sizeof(data)/sizeof(data[0]);
    Tree *tree;
    int start=0;
    Create(tree,data,start,len);
    Print(tree);
    return 0;
} 

给你修改好了，如果问题解决，麻烦点下我回答右边的采纳，并且同时采纳下 https://ask.csdn.net/questions/703113

// Q703225.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"


#include <iostream>
using namespace std;
#include <stdlib.h>
#define NULLVALUE 0

typedef int Elemtype;

typedef struct Tree{
    Elemtype data;
    struct Tree *LTree;
    struct Tree *RTree;
};

void Create(Tree **tree,Elemtype *data,int &start,int len){
    if(start>=len||data[start]==NULLVALUE){
        *tree = NULL;
        return ;
    }
    else{
        *tree=(Tree *)malloc(sizeof(Tree));
        (*tree)->data=data[start];
        ++start;
        Create(&(*tree)->LTree,data,start,len);
        ++start;
        Create(&(*tree)->RTree,data,start,len);
    }
}

void Print(Tree *tree){
    if(tree==NULL)
        return ;
    cout<<tree->data<<"  ";
    Print(tree->LTree);
    Print(tree->RTree);
}

int main(){
    Elemtype data[]={1,2,4,0,0,5,0,0,3,6,0,0,7};
    int len=sizeof(data)/sizeof(data[0]);
    Tree *tree=NULL;
    int start=0;
    Create(&tree,data,start,len);
    Print(tree);
    return 0;
}