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Dushanbe Metro Mystery Cache

Difficulty:
4 out of 5
Terrain:
2 out of 5

Size: Size:   micro (micro)

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Geocache Description:


Dushanbe, the capital of Tajikistan, does not have a metro. So let's plan one!

There will be two lines:

Line 1 - The Red Line - West/East (7 stations)
Line 2 - The Blue Line - North/South (8 stations)

To make the planning a bit easier for you, here are the schematic views of all possible connections of the two metro grids. The numbers on the edges are the expected commuting times between the different stations (not to scale).

Please remember, we're in the planning phase, so none of the stations and tunnels/tracks are built yet - all of this only exists on paper (or on the computer rather) for now.

 


Your task is now to find the MST, the minimum spanning tree, for the two grids. You need to use an algorithm for this, but as the two grids are rather limited in size, this can be done "by hand". You don't need a computer for this algorithm. 

The MST we are looking for will enable us to reach all of the metro stations in one grid in the overall shortest time. There will be other things to consider (number of tracks, potential loops, etc.), but for this exercise we are really just looking at minimizing the overall commuting time in the grid. 

In any case, when you have identified the two MSTs, write down the Red Line values from left to right and the Blue Line values from top to bottom.

Your coordinates in UTM format are: 42S xxxxxx xxxxxxx

You can convert the UTM coordinates into different coordinate formats here.

If you have any questions, feel free to ask. I don't want to annoy anybody with the puzzles, they are supposed to be fun, entertaining and sometimes also educational. I mean, where else do you come across algorithms these days?

Happy hunting!

 

You can check your answers for this puzzle on GeoChecker.com.




Additional Hints (Decrypt)

Vaqbbe chmmyr: Xehfxny'f nytbevguz fubhyq uryc Bhgqbbe frnepu: oruvaq gur terl obk, snpvat gur fgerrg, zntargvp

Decryption Key

A|B|C|D|E|F|G|H|I|J|K|L|M
-------------------------
N|O|P|Q|R|S|T|U|V|W|X|Y|Z

(letter above equals below, and vice versa)