我正在尝试编写从排序数组创建BST的代码。这是我到目前为止得到的代码:

#include <bits/stdc++.h>
using namespace std;

struct Node {
    int data;
    Node *left;
    Node *right;
    Node (int v) {
        data = v;
        left = right = NULL;
    }
}

Node* createBST(int arr[], int start, int end) {
    if (end <= start)
        return NULL;
    int mid = (start+end)/2;
    Node* root = new Node(arr[mid]);
    root->left = createBST(arr, start, mid);
    root->right = createBST(arr, mid+1, end);
    return root;
}

void inorder(Node* root) {
    if (root == NULL)
        return;
    inorder(root->left);
    cout<<root->data<<" ";
    inorder(root->right);
}

int main() {
    int t, n, i;
    cin>>t;
    while (t--) {
        cin>>n;
        int arr[n];
        for (i=0; i<n; i++)
            cin>>arr[i];
        Node* root = createBST(arr, 0, n);
        inorder(root);
        cout<<endl;
    }
    return 0;
}

我在其中编写此代码的GeeksforGeeks沙箱会抛出以下错误:

Compilation Error:
prog.cpp:14:5: error: expected initializer before * token
 Node* createBST(int arr[], int start, int end) {
     ^
prog.cpp: In function int main():
prog.cpp:40:38: error: createBST was not declared in this scope
      Node* root = createBST(arr, 0, n);
                                      ^

我不知道我做错了什么。