f you want to solve a tricky problem, it often helps to get organized. You might, for example, break the problem into pieces and tackle the easiest pieces first. But this kind of sorting has a cost. You may end up spending too much time putting the pieces in order.

This dilemma is especially relevant to one of the most iconic problems in computer science: finding the shortest path from a specific starting point in a network to every other point. It’s like a souped-up version of a problem you need to solve each time you move: learning the best route from your new home to work, the gym and the supermarket.

“Shortest-paths is a beautiful problem that anyone in the world can relate to,” said Mikkel Thorup (opens a new tab), a computer scientist at the University of Copenhagen.

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“This thing might as well have been discovered 50 years ago, but it wasn’t,” Thorup said. “That makes it that much more impressive.”

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