public void ThreeNodes()
{
var bstGenerator = new UniqueBst2();
var trees = bstGenerator.GenerateTrees(3);
Assert.Equal(5, trees.Count);
}
public void TwoNodes()
{
var bstGenerator = new UniqueBst2();
var trees = bstGenerator.GenerateTrees(2);
Assert.Equal(2, trees.Count);
var root1 = trees[0];
Assert.Equal(1, root1.val);
Assert.Equal(2, root1.right.val);
var root2 = trees[1];
Assert.Equal(2, root2.val);
Assert.Equal(1, root2.left.val);
}