Seven Bridges to Cross
Programming Snapshot – Graph Theory
Pretty much any computer science lecture about graph theory covers the "Seven Bridges of Königsberg" problem. Mike Schilli puts a Python script to work on a solution, but finds that a new bridge must be built.

The task of crossing the seven bridges over the Pregola River on a city tour of Königsberg (nowadays known as Kaliningrad) without missing one or walking across one twice [1] is simply captivating.
The Swiss mathematician Leonhard Euler already proved that this was impossible as early as 1736, but the task is still useful as a mathematical brain teaser today because the network of bridges can be converted into a graph (Figure 1) and bombarded with graph-theory axioms and algorithms.
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