The Algorithm Still Running Your GPS: Edsger Dijkstra and His Impact on CS

Week 07 of the Turing Award Series: shortest paths, semaphores, and why testing was never enough.

I am sure every CS student has heard of Dijkstra and his algorithm for finding the shortest path. What is relatively less well known is his invention of semaphores and his push toward proving code correct, not just testing and debugging it. This chapter took me a while because there is so much Dijkstra contributed to computer science, and he did it in an idiosyncratic way.

I have read this quote so many times and never knew it was attributed to Dijkstra: "Program testing can be used to show the presence of bugs, but never to show their absence."

Code, a runnable demo, and the full writeup: https://github.com/nirmal91/turing-award-series/tree/main/07...