AlgoScope

2-3 Tree

Data structureadvancedBalanced Search Trees

A perfectly balanced search tree whose nodes hold one or two keys.

Decision · step 5 of 17B-Tree: A 2-3 tree grows by splitting
10 20 30×

10 20 30 has 3 keys and the limit is 2, so it splits. The middle key, 20, moves up to the parent; the keys below it form the left node and the keys above it the right node.

Open in the player →or start at step 5

What you will see

Overfull nodes split and push a key up; height grows only at the root.

How b-tree works →

Cost

searchO(log n)
insertO(log n)
deleteO(log n)
SpaceO(n)

How you work with it here

play it through, step one change at a time, scrub to any step, run it on your own input, try operations in any order.

Screen readers: Each element is an accessibility element with position, value and state; structural changes are announced per step.

Reduced motion: Elements appear at their destination with a crossfade; no travel longer than the element's own size.

Leads to

Topics that need this one first.

Taught by the same lesson

B-Tree covers these too, in the same run.