Algorithm visualizer

See every step, with your own input

Pick an algorithm, enter your own numbers or use a preset, then step through the run. The pseudocode and the explanation follow each step.

Arrays and searching

Sorting

Stacks, queues and Fenwick tree

Trees and tries

Graphs

Dynamic programming

Greedy and backtracking

Segment tree: range minimum

Each node stores the minimum of a range, and the root covers everything. A query combines a few nodes that exactly cover the range, and an update recomputes only the nodes above one leaf.

Try it yourself

Query the range [1, 2] after an update at index 1 to a small value. Which node's stored value changes first?

Step through the run

Step 1 of 29

Array528193

waiting
current
finished

Leaf [0, 0] stores a[0] = 5.

Speed

Labels under values name their role, such as lo, hi, mid, i, j, min, L and R. Faded items are already ruled out or already in place.

Segment tree: range minimum

Each node stores the minimum of a range, and the root covers everything. A query combines a few nodes that exactly cover the range, and an update recomputes only the nodes above one leaf.