Maximum weight matching with repeated nodes












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We are given two sets of nodes $A$ and $B$ forming a graph where each element $x in A$ can be connected with an element $y in B$ with different possible weights. The graph can be explained in two ways.




  1. There are multiple edges possible between elements of $X$ and $Y$ having different weights.


  2. Elements of $A$ can be matched with repeated nodes of elements of $B$ with different edge weights.



Let $E(x)$ be the set of edges involving element x. Then the maximum weight matching problem can be formulated as follows:



Let $x_{ij}$ takes value 1, if edge $(i, j) in E$ is selected and $w_{ij}$ be weight of edge $(i, j) in E$.



$$text{minimize} sum_{(i, j) in E} x_{ij}w_{ij}$$
$$sum_{j in E(i)}x_{ij} le 1 forall i in A$$
$$sum_{i in E(j)}x_{ij} le 1 forall j in B$$
$$x_{ij} = {0, 1} quad forall (i, j) in E$$



My question is whether this problem satisfy the total unimodularity condition. If it does, how can we prove it? I know proof for the standard problem where you consider submatrices and find the determinant.



Can we still use network flow algorithms to solve this problem?










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    We are given two sets of nodes $A$ and $B$ forming a graph where each element $x in A$ can be connected with an element $y in B$ with different possible weights. The graph can be explained in two ways.




    1. There are multiple edges possible between elements of $X$ and $Y$ having different weights.


    2. Elements of $A$ can be matched with repeated nodes of elements of $B$ with different edge weights.



    Let $E(x)$ be the set of edges involving element x. Then the maximum weight matching problem can be formulated as follows:



    Let $x_{ij}$ takes value 1, if edge $(i, j) in E$ is selected and $w_{ij}$ be weight of edge $(i, j) in E$.



    $$text{minimize} sum_{(i, j) in E} x_{ij}w_{ij}$$
    $$sum_{j in E(i)}x_{ij} le 1 forall i in A$$
    $$sum_{i in E(j)}x_{ij} le 1 forall j in B$$
    $$x_{ij} = {0, 1} quad forall (i, j) in E$$



    My question is whether this problem satisfy the total unimodularity condition. If it does, how can we prove it? I know proof for the standard problem where you consider submatrices and find the determinant.



    Can we still use network flow algorithms to solve this problem?










    share|cite|improve this question









    New contributor




    Dan is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
    Check out our Code of Conduct.























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      We are given two sets of nodes $A$ and $B$ forming a graph where each element $x in A$ can be connected with an element $y in B$ with different possible weights. The graph can be explained in two ways.




      1. There are multiple edges possible between elements of $X$ and $Y$ having different weights.


      2. Elements of $A$ can be matched with repeated nodes of elements of $B$ with different edge weights.



      Let $E(x)$ be the set of edges involving element x. Then the maximum weight matching problem can be formulated as follows:



      Let $x_{ij}$ takes value 1, if edge $(i, j) in E$ is selected and $w_{ij}$ be weight of edge $(i, j) in E$.



      $$text{minimize} sum_{(i, j) in E} x_{ij}w_{ij}$$
      $$sum_{j in E(i)}x_{ij} le 1 forall i in A$$
      $$sum_{i in E(j)}x_{ij} le 1 forall j in B$$
      $$x_{ij} = {0, 1} quad forall (i, j) in E$$



      My question is whether this problem satisfy the total unimodularity condition. If it does, how can we prove it? I know proof for the standard problem where you consider submatrices and find the determinant.



      Can we still use network flow algorithms to solve this problem?










      share|cite|improve this question









      New contributor




      Dan is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.











      We are given two sets of nodes $A$ and $B$ forming a graph where each element $x in A$ can be connected with an element $y in B$ with different possible weights. The graph can be explained in two ways.




      1. There are multiple edges possible between elements of $X$ and $Y$ having different weights.


      2. Elements of $A$ can be matched with repeated nodes of elements of $B$ with different edge weights.



      Let $E(x)$ be the set of edges involving element x. Then the maximum weight matching problem can be formulated as follows:



      Let $x_{ij}$ takes value 1, if edge $(i, j) in E$ is selected and $w_{ij}$ be weight of edge $(i, j) in E$.



      $$text{minimize} sum_{(i, j) in E} x_{ij}w_{ij}$$
      $$sum_{j in E(i)}x_{ij} le 1 forall i in A$$
      $$sum_{i in E(j)}x_{ij} le 1 forall j in B$$
      $$x_{ij} = {0, 1} quad forall (i, j) in E$$



      My question is whether this problem satisfy the total unimodularity condition. If it does, how can we prove it? I know proof for the standard problem where you consider submatrices and find the determinant.



      Can we still use network flow algorithms to solve this problem?







      optimization discrete-optimization bipartite-graph matching-theory






      share|cite|improve this question









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      Check out our Code of Conduct.











      share|cite|improve this question









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      Check out our Code of Conduct.









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      edited Jan 4 at 5:52







      Dan













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      asked Jan 4 at 5:30









      DanDan

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