public class BinarySearchTree {
    int node;
    BinarySearchTree left;
    BinarySearchTree right;
}

BinarySearchTree createBinarySearchTree(BinarySearchTree tree, int[] array, int start, int end) {
    if (array.length == 0) {
        return null;
    }

    if (array.length == 1) {
        tree.node = array[0];
        return tree;
    }

    tree.node = array[array.length / 2];
    tree.left = createBinarySearchTree(tree.left, array, start, (array.length / 2) - 1);
    tree.right = createBinarySearchTree(tree.left, array, (array.length / 2) + 1, end);

    return tree;
}