It became such when true claster analysis began
or inner structure of each claster is forgotten and clasters  are simple poins again.
Some time I was tried to trace complicated inner structure but failed.

yes. love the problem.

some tests:

5   0 0     0 1     0 2     0 4     0 5
5   0 0     0 1     0 3     0 4     0 5
0

1011

Distance must be strictly less