private bool RemoveNode(AVLTreeNode <T> current) { if (current == null || current._tree != this) { return(false); } var parent = current.Parent; //Case: no right child if (current == Head) { Head = null; } if (current.Right == null) { if (parent == null) { Head = current.Left; } else { int compare = parent.Value.CompareTo(current.Value); if (compare > 0) { parent.Left = current.Left; } else { parent.Right = current.Left; } } } //Case: the right child don't have left child else if (current.Right.Left == null) { current.Right.Left = current.Left; if (parent == null) { Head = current.Right; } else { int compare = parent.Value.CompareTo(current.Value); if (compare > 0) { parent.Left = current.Right; } else { parent.Right = current.Right; } } } //Case: the right child has a left child else { AVLTreeNode <T> leftMost = current.Right.Left; AVLTreeNode <T> leftMostParent = current.Right; while (leftMost.Left != null) { leftMostParent = leftMost; leftMost = leftMostParent.Left; } leftMostParent.Left = leftMost.Right; leftMost.Left = current.Left; leftMost.Left = current.Right; if (parent == null) { Head = leftMost; } else { int compare = parent.Value.CompareTo(current.Value); if (compare > 0) { parent.Left = leftMost; } else { parent.Right = leftMost; } } } return(true); }