This program is (or will be) a Scotland Yard helper that calculates the possible positions of Mr. X given a starting position and a list of tickets.
networkx is required.
At the command promt enter
cd path/to/scotlandyard
python(3) scotlandyard.py startnode ticketlist
with startnode being a number between 1 and 199 and ticketlist being a combination of taxi, bus, subway or black. For example:
python scotlandyard.py 27 taxi taxi bus subway
yields the result 46, 67, 79, 89, 111.