INSTANCE:
Set C of m cities, an initial city ,
distances
satisfying the triangle inequality.
SOLUTION:
A collection of k subtours, each containing the initial city s, such that
each city is in at least one subtour.
MEASURE:
The maximum length of the k subtours.
Good News:
Approximable within 1-1/k plus the performance ratio of the MINIMUM METRIC TRAVELING SALESPERSON PROBLEM,
i.e., within
[171].
Comment:
The non-metric variation in which the graph is a tree and k possibly
different initial cities are given in the input is approximable within
2-2/(p+1) [48].