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The.Algorithm.Design.Manual.Springer-Verlag.1998

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Traveling Salesman Problem<br />

Next: Hamiltonian Cycle Up: Graph Problems: Hard Problems Previous: Vertex Cover<br />

Traveling Salesman Problem<br />

Input description: A weighted graph G.<br />

Problem description: Find the cycle of minimum cost that visits each of the vertices of G exactly once.<br />

Discussion: <strong>The</strong> traveling salesman problem is the most notorious NP-complete problem. This is a<br />

function of its general usefulness, and because it is easy to explain to the public at large. Imagine a<br />

traveling salesman who has to visit each of a given set of cities by car. What is the shortest route that will<br />

enable him to do so and return home, thus minimizing his total driving?<br />

Although the problem arises in transportation applications, its most important applications arise in<br />

optimizing the tool paths for manufacturing equipment. For example, consider a robot arm assigned to<br />

solder all the connections on a printed circuit board. <strong>The</strong> shortest tour that visits each solder point<br />

exactly once defines the most efficient path for the robot. A similar application arises in minimizing the<br />

amount of time taken by a graphics plotter to draw a given figure.<br />

Several issues arise in solving TSPs:<br />

● Is the graph unweighted? - If the graph is unweighted, or all the edges have one of two cost<br />

file:///E|/BOOK/BOOK4/NODE175.HTM (1 of 5) [19/1/2003 1:31:21]

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