Consider the grid shown below.
There are 4 electrical "switch pairs" which need to be connected to make the overall connection work.
--------------------------------------------------------- | | | | | | | | | | | | | | |
--------------------------------------------------------- | | | | | | | | | | | | | | c`|
--------------------------------------------------------- | | | | | | | | | | | | | | |
--------------------------------------------------------- | | | | b | | | | | | | | | | |
--------------------------------------------------------- | | | | | | | | | | | | | d'| |
--------------------------------------------------------- | | | | | | | | | | | | | | |
--------------------------------------------------------- | | | | | | | | | | | | | | |
--------------------------------------------------------- | | | | | | a | | | | | a`| | | |
--------------------------------------------------------- | | | | | | | | | | | | | | |
--------------------------------------------------------- | | | | | | | | | | | | | | |
--------------------------------------------------------- | | | | | | | | | | | b`| | | |
--------------------------------------------------------- | | | | | | | d | | | | | | | |
--------------------------------------------------------- | | | | | | | | | | | | | | |
--------------------------------------------------------- | | c | | | | | | | | | | | | |
---------------------------------------------------------
The paths are
a --- a' (path A) b --- b' (path B) c --- c' (path C) d --- d' (path D)
There would be two possible routes to connect these paths. The connection can follow either 1) horizontal then vertical direction, or 2) vertical then horizontal direction. There ie no other way that the path between the electrical switches could be made. Thus every possible path here would make a bounded rectangle encompassing the pair of switches.
The following rule is to be followed for making up these paths:
If a switch p belonging to one path lies in the bounded rectangle formed by the switches belonging to another path, then path p must be connected first.
SO - What would be the order of connectivity of this set of paths?
AND - Develop a generalized procedure to implement this strategy!
Thanks, Chris