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Four color theorem problem

  1. Sep 13, 2011 #1
  2. jcsd
  3. Sep 13, 2011 #2


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    Gold Member

    Basically, what they mean is that the four color theorem only applies to maps that have all "countries" in one piece. If you allow disconnected countries, then you may need more than 4 colors, and the map given in that book is an example where you would need 5.
  4. Sep 14, 2011 #3
    I imagine there is no limit if you allow disconnected countries.

    Let n be a natural number. Simple arrange all the n countries as "slices of pie" into circles in all the various combinations and orders. Then we will need n different colours to colour the map.
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