2-3-4 and red-black Trees
	• A 2-3-4 tree solves this problem – a node can either be a leaf or, – if it has 1 data item there are 2 children, – 2 data items has 3 children, and – 3 data items has 4 children • A 2-3-4 tree remains perfectly balanced – but its insertion algorithm splits the nodes as it traverses down the tree toward a leaf, rather than upon the return to the root