C++创建二叉排序树

typedef struct node{
    int data;
    struct node*left,*right;
}node,*Tree;
void create(Tree &t,int val) {
    if (t == nullptr) {
        t = new node;
        t->data = val;
        t->left = t->right = nullptr;
    }
    else if (val > t->data)
        create(t->right, val);
    else if (val < t->data)
        create(t->left, val);
}
void insert(Tree& t, int a[], int len) {
    for (int i = 0;i < len;i++) {
        create(t, a[i]);
    }
}
int main(){
    Tree t=nullptr;
    int a[]={1,2,3,4,5,6};
    insert(t,a,6);
}