Magic labeling of the octahedron graph












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A magic labeling of a graph $G$ with $q$ edges is an edge labeling by the numbers $1, 2, 3, ldots, q $ so that the sum of the labels of all the edges incident with any vertex is the same.



We need to find a magic labeling of the octahedron graph. I found this problem in Pearls in Graph Theory by Hartfield and Ringel in the chapter Labeling Graphs.



I tried to find such a labeling by solving a system of linear equations with some conditions since we know that each vertex will have a total of $frac{2cdotsum_{i=1}^{12}i}{6}$.



Are there other ways of finding such a labeling?



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1












$begingroup$


A magic labeling of a graph $G$ with $q$ edges is an edge labeling by the numbers $1, 2, 3, ldots, q $ so that the sum of the labels of all the edges incident with any vertex is the same.



We need to find a magic labeling of the octahedron graph. I found this problem in Pearls in Graph Theory by Hartfield and Ringel in the chapter Labeling Graphs.



I tried to find such a labeling by solving a system of linear equations with some conditions since we know that each vertex will have a total of $frac{2cdotsum_{i=1}^{12}i}{6}$.



Are there other ways of finding such a labeling?



enter image description here










share|cite|improve this question











$endgroup$








  • 1




    $begingroup$
    I couldn't find the other question by clicking on your user name. Is it under another account? There are instructions on the FAQ on how to merge accounts.
    $endgroup$
    – Ross Millikan
    Jan 29 at 15:05










  • $begingroup$
    I have added the link now.
    $endgroup$
    – Geek
    Jan 29 at 15:19














1












1








1


1



$begingroup$


A magic labeling of a graph $G$ with $q$ edges is an edge labeling by the numbers $1, 2, 3, ldots, q $ so that the sum of the labels of all the edges incident with any vertex is the same.



We need to find a magic labeling of the octahedron graph. I found this problem in Pearls in Graph Theory by Hartfield and Ringel in the chapter Labeling Graphs.



I tried to find such a labeling by solving a system of linear equations with some conditions since we know that each vertex will have a total of $frac{2cdotsum_{i=1}^{12}i}{6}$.



Are there other ways of finding such a labeling?



enter image description here










share|cite|improve this question











$endgroup$




A magic labeling of a graph $G$ with $q$ edges is an edge labeling by the numbers $1, 2, 3, ldots, q $ so that the sum of the labels of all the edges incident with any vertex is the same.



We need to find a magic labeling of the octahedron graph. I found this problem in Pearls in Graph Theory by Hartfield and Ringel in the chapter Labeling Graphs.



I tried to find such a labeling by solving a system of linear equations with some conditions since we know that each vertex will have a total of $frac{2cdotsum_{i=1}^{12}i}{6}$.



Are there other ways of finding such a labeling?



enter image description here







combinatorics discrete-mathematics graph-theory






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edited Jan 29 at 16:11







Geek

















asked Jan 29 at 14:53









GeekGeek

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  • 1




    $begingroup$
    I couldn't find the other question by clicking on your user name. Is it under another account? There are instructions on the FAQ on how to merge accounts.
    $endgroup$
    – Ross Millikan
    Jan 29 at 15:05










  • $begingroup$
    I have added the link now.
    $endgroup$
    – Geek
    Jan 29 at 15:19














  • 1




    $begingroup$
    I couldn't find the other question by clicking on your user name. Is it under another account? There are instructions on the FAQ on how to merge accounts.
    $endgroup$
    – Ross Millikan
    Jan 29 at 15:05










  • $begingroup$
    I have added the link now.
    $endgroup$
    – Geek
    Jan 29 at 15:19








1




1




$begingroup$
I couldn't find the other question by clicking on your user name. Is it under another account? There are instructions on the FAQ on how to merge accounts.
$endgroup$
– Ross Millikan
Jan 29 at 15:05




$begingroup$
I couldn't find the other question by clicking on your user name. Is it under another account? There are instructions on the FAQ on how to merge accounts.
$endgroup$
– Ross Millikan
Jan 29 at 15:05












$begingroup$
I have added the link now.
$endgroup$
– Geek
Jan 29 at 15:19




$begingroup$
I have added the link now.
$endgroup$
– Geek
Jan 29 at 15:19










1 Answer
1






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oldest

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$begingroup$

A possible solution would be:



$x_1 = 1$



$x_2 = 2$



$x_3 = 9$



$x_4 = 6$



$x_5 = 11$



$x_6 = 12$



$x_7 = 7$



$x_8 = 8$



$x_9 = 10$



$x_{10} = 4$



$x_{11} = 3$



$x_{12} = 5$



One way to make things easier is to compute which has to be the sum of the edges incident to each vertex. In this case, the sum of all edges $1+2+3+4+5+6+7+8+9+10+11+12 = 78$.



If we add the sum of the edges incident to each vertex, we will be counting each edge twice, meaning that we will get $2cdot 78 = 156$. Since there are 6 vertices, the sum of the edges incident to each vertex is $frac{156}{6}=26$. This may be helpful when trying to solve this kind of problems.






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    1 Answer
    1






    active

    oldest

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    1 Answer
    1






    active

    oldest

    votes









    active

    oldest

    votes






    active

    oldest

    votes









    2












    $begingroup$

    A possible solution would be:



    $x_1 = 1$



    $x_2 = 2$



    $x_3 = 9$



    $x_4 = 6$



    $x_5 = 11$



    $x_6 = 12$



    $x_7 = 7$



    $x_8 = 8$



    $x_9 = 10$



    $x_{10} = 4$



    $x_{11} = 3$



    $x_{12} = 5$



    One way to make things easier is to compute which has to be the sum of the edges incident to each vertex. In this case, the sum of all edges $1+2+3+4+5+6+7+8+9+10+11+12 = 78$.



    If we add the sum of the edges incident to each vertex, we will be counting each edge twice, meaning that we will get $2cdot 78 = 156$. Since there are 6 vertices, the sum of the edges incident to each vertex is $frac{156}{6}=26$. This may be helpful when trying to solve this kind of problems.






    share|cite|improve this answer









    $endgroup$


















      2












      $begingroup$

      A possible solution would be:



      $x_1 = 1$



      $x_2 = 2$



      $x_3 = 9$



      $x_4 = 6$



      $x_5 = 11$



      $x_6 = 12$



      $x_7 = 7$



      $x_8 = 8$



      $x_9 = 10$



      $x_{10} = 4$



      $x_{11} = 3$



      $x_{12} = 5$



      One way to make things easier is to compute which has to be the sum of the edges incident to each vertex. In this case, the sum of all edges $1+2+3+4+5+6+7+8+9+10+11+12 = 78$.



      If we add the sum of the edges incident to each vertex, we will be counting each edge twice, meaning that we will get $2cdot 78 = 156$. Since there are 6 vertices, the sum of the edges incident to each vertex is $frac{156}{6}=26$. This may be helpful when trying to solve this kind of problems.






      share|cite|improve this answer









      $endgroup$
















        2












        2








        2





        $begingroup$

        A possible solution would be:



        $x_1 = 1$



        $x_2 = 2$



        $x_3 = 9$



        $x_4 = 6$



        $x_5 = 11$



        $x_6 = 12$



        $x_7 = 7$



        $x_8 = 8$



        $x_9 = 10$



        $x_{10} = 4$



        $x_{11} = 3$



        $x_{12} = 5$



        One way to make things easier is to compute which has to be the sum of the edges incident to each vertex. In this case, the sum of all edges $1+2+3+4+5+6+7+8+9+10+11+12 = 78$.



        If we add the sum of the edges incident to each vertex, we will be counting each edge twice, meaning that we will get $2cdot 78 = 156$. Since there are 6 vertices, the sum of the edges incident to each vertex is $frac{156}{6}=26$. This may be helpful when trying to solve this kind of problems.






        share|cite|improve this answer









        $endgroup$



        A possible solution would be:



        $x_1 = 1$



        $x_2 = 2$



        $x_3 = 9$



        $x_4 = 6$



        $x_5 = 11$



        $x_6 = 12$



        $x_7 = 7$



        $x_8 = 8$



        $x_9 = 10$



        $x_{10} = 4$



        $x_{11} = 3$



        $x_{12} = 5$



        One way to make things easier is to compute which has to be the sum of the edges incident to each vertex. In this case, the sum of all edges $1+2+3+4+5+6+7+8+9+10+11+12 = 78$.



        If we add the sum of the edges incident to each vertex, we will be counting each edge twice, meaning that we will get $2cdot 78 = 156$. Since there are 6 vertices, the sum of the edges incident to each vertex is $frac{156}{6}=26$. This may be helpful when trying to solve this kind of problems.







        share|cite|improve this answer












        share|cite|improve this answer



        share|cite|improve this answer










        answered Jan 29 at 15:45









        maxbpmaxbp

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