如何将我的函数更改为构造函数？

Question

我需要创建一个参数化的构造函数，在给定排序数组的情况下创建一个完美平衡的二叉搜索树。我知道如何创建一个创建 BST 的函数，但是如何从构造函数中创建 BST？ 这是我的功能：

    node * sortedArrayBST(double * arr, int start, int end)
    {
        int mid = (start + end)/2;
        if (start > end)
        {
            return NULL;
        }
        //because the array will be sorted
        //the root of the tree will contain the item in the middle of the array so everything less than the middle will go in the left subtree
        //and everything greater than the middle will go in the right subtree

        node * root = new node(arr[mid]);
        //recursively make left subtree
        root->left = sortedArrayBST(arr, start, end-1);
        //recursively make left subtree
        root->right = sortedArrayBST(arr, mid + 1, end);

        return root;
    }

Answer 1

class BST
{
public:
      BST (double * arr, int start, int end)
      {
          int mid = (start + end)/2;
          if (start > end)
          {
              std::cerr << "Invalid BST tree."
          }
          //because the array will be sorted
          //the root of the tree will contain the item in the middle of the array so everything less than the middle will go in the left subtree
          //and everything greater than the middle will go in the right subtree

          root = new node(arr[mid]);
          node *temp, *parent;
          for (num = arr[mid/2]; start <= end;)
             if (num <= arr[end]){
                parent = temp;
                temp=temp->left;
                end = (start + end)/2;
             } else {
                parent = temp;
                temp=temp->right;
                start = (start + end)/2;
             }
          }
          //recursively make left subtree
          root->right = sortedArrayBST(arr, mid + 1, end);
      }
private :
      node * root;
}