a distance matrix (such as the type at the back of a road atlas
of Britain), containing all the distances between all cities on
the tour. 2. Find the shortest distance and link these two
cities together. 3. Then, find the second shortest distance, and
link these two cities. 4. Now, find the next smallest edge whose
cities conform to the following a) Both must have an edge degree
ratio <=1 (i.e. neither can already be linked to more than one
other city) b) Adding an edge between the cities must not result
in a closed tour, which does not already include all the cities
on the tour. 5. Repeat until all cities end up being connected
to two other cities. Identify the two closest cities (shown in
red). Join the closest cities together. They now have one edge
each (signified by grey colouring). Now find the next two
closest Join them together. Now find the two closest cities,
where joining them will not result in a closed tour, and where
each has an edge degree of either one (denoted by grey shading)
or zero (transp