Russell Eveleigh is using a Raspberry Pi Pico to demonstrate Dijkstra's algorithm visually with LEDs arranged as a map of the Cotswolds in England.

In one specific sense, this version of Dijkstra’s algorithm is the best possible. That was the last word on the standard version of the problem for nearly 40 years.

The original version of this article implied that Dijkstra’s original shortest-path algorithm, from the 1950s, achieved the theoretical speed limit for positive-weight graphs. In fact, the speed limit ...