# Tokyo Metro puzzle special #2: The tour of the Metro

This is a simpler puzzle: How many stations do you have to pass by to pass by every station of the Metro? map

Please either 1) explain your solution or 2) make an image of the route. Once consensus has decided that a particular one is the least, I will accept that answer.

Clarification:

1. Stations under the same name (like Ueno G16 H17) only have to be passed once, but stations under different names that are listed as connecting to each other (like Akihabara H15 and Iwamotocho S08) needed to be passed once for each name.
• I'm not sure I understand... Don't you have to pass by all the stations to pass by all the stations? – Yout Ried Mar 6 at 4:37
• yes but for some of them you need to pass by them 2 times or more since you do only one route – Joey Dionne Mar 6 at 4:49
• Kinda like the knight's tour. – Tzu Li Mar 7 at 3:46
• Has a correct answer been given? If so, please don't forget to $\color{green}{\checkmark \small\text{Accept}}$ it. If not, some responses to the answerers to help steer them in the right direction would be helpful. – Rubio Mar 9 at 7:24

The route I found is passing by

292 stations

A lot of stations need to be visited twice because they are at the end of the lines and there is only one way back so I started and ended at the tho longest end of lines to help reduce the station count.

Starting at Nichi-Takashimadaira I27 and ending at Nichi-Funabachi T23. I'm only using metro lines. I also assume that M08 is Shinjuku-Nishiguchi and not Shinjuku. In bold are the stations where I pass more than once.

I27-I26-I25-I24-I23-I22-I21-I20-I19-I18-I17-I16-I15-I14-I13-I12/E07-I11-S06/I10/Z07-S05/Z06/T07-Z05-S05/Z06/T07-T08-I09/C11/T09/M18/Z08-C10-I08/C09/H07-M15/H06/C08-H05-M15/H06/C08-M14/C07-C06-C05-C06-M14/C07-G05/M13-G06/N06-G07-G06/N06-N05-N04/E22-E21-N04/E22-H04/E23-H03-H02-H01-H02-H03-H04/E23-N04/E22-I03/N03-I02/N02-I01/N1-I02/N02-I03/N03-I04/A08-A07-A06-A05-A04-A03-A02-A01-A02-A03-A04-A05-A06-A07-I04/A08-I05-I06-I07-I08/C09/H07-Y18-Y19-Y18-Y17-N07/Z04/Y16-Y15-S04/Y14/N09-S03-S04/Y14/N09-M12/N08-M11-M10-F13/S02/M09-F14-C03/F15-C02-C01-C02-C03/F15-Z01/F16/G01-Z02/G02/C04-G03/E24/Z03/G04-E25-E26-S01/E27-E28-E29-M06/E30-MB05-MB04-MB03-MB04-MB05-M06/E30-M05-M04-M03-M02-M01-M02-M03-M04-M05-M06/E30-E31-E32-E33-E34-E35-E36-E37-E38-E37-E36-E35-E34-E33-E32-E31-M06/E30-M07-E01/M08-E02/F12-E03-E04-E05-E06/T06/Y13/N10-T05-T04-T03-T02-T01-T02-T03-T04-T05-E06/T06/Y13/N10-Y12-Y11-Y10-Y09/F09/M25-F10-F11-F10-Y09/F09/M25-F08/Y08-F07/Y07-F06/Y06-F05/Y05-F04/Y04-F03/Y03-F02/Y02-F01/Y01-F02/Y02-F03/Y03-F04/Y04-F05/Y05-F06/Y06-F07/Y07-F08/Y08-Y09/F09/M25-M24-M23-N11/M22-N12-N13-N14-N15-N16-N17-N18-N19-N18-N17-N16-N15-N14-N13-N12-N11/M22-E08/M21-M20-M19-S07-C12-C13-C14-C15-C16-C17-C18/H21-C19-C20-C19-C18/H21-H20-J19-H18-G16/H17-G17-G18-G19/A18-A19-A20/Z14-Z13-Z12/S13-S14-S15-S16-S17-S18-S19-S20-S21-S20-S19-S18-S17-S16-S15-S14-Z12/S13-S12-S11/E13-E14/Z11-Z10-A14/H13-H14-H15-S08-A15/S09-S10-S11/E13-E12-A17/E11-A16-A17/E11-E10-E09-H16-G15-G14-G13-Z09/G12-I09/C11/T09/M18/Z08-M17-M16/H08/G09-G10-G11/T10/A13-A12-A11/H09-A10/G08-A09/E20-E19-E18-E17-Y21/E16-Y22-Y23-Y24-Y23-Y22-Y21/E16-Y20-H10-H11-H12/T11-E15/T12-T13-T14-T15-T16-T17-T18-T19-T20-T21-T22-T23

There is 76 extra stations in that solution but at least 64 of them can't be removed because of the end of lines, that leaves 12 extra stations that can maybe be removed by a shorter route

The stations that can possibly be removed of my route are M15/H06/C08, C06, M14/C07, G06/N06, N04/E22 twice, Y18, S04/Y14/N09, F10, Y09/F09/M25, S11/E13 and A17/E11.

• Ehm... I think that you missed a couple of stations: H15, S08, H14, A14/H13, Z10, E14/Z11, S10, and S07. Please revise your answer! – Tzu Li Mar 7 at 3:45
• The first 7 stations are there in the part of the route: E14/Z11-Z10-A14/H13-H14-H15-S08-A15/S09-S10. It's near the end, just before the bold S11/E13. S07 is also there but as C12/S07/M19 after the long bold N18-11 line, but I just saw that it's three different stations and not just one, I'll correct that. – Joey Dionne Mar 7 at 4:17
• Oops. Sorry about that! – Tzu Li Mar 7 at 4:23