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

Sliding window: best sum of k values

Keep a window of k values. Each slide adds one value on the right and removes one on the left, so each slide costs O(1).

Change k from 3 to 2 on the same array. Which window wins now, and does the best sum change in the same way?

Step 1 of 8

win

First window a[0..2]: sum = 8. Best = 8.

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.

Sliding window: best sum of k values

Keep a window of k values. Each slide adds one value on the right and removes one on the left, so each slide costs O(1).