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

Bubble sort

Repeatedly swap neighbours that are out of order. Each pass pushes the largest unsorted value to the end.

Compare with

Count the swaps for the descending preset. Can you give a formula for it in terms of n?

Step 1 of 44

Start: nothing is in its final place yet.

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.