Proof of NP-completeness for the following












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I have encountered a problem similar to Set Cover (and Maximum Coverage):



We have several sets in a universe with $N$ elements. What is the maximum number of sets so that the number of elements found in these sets is not greater than $frac{N}{2}$.



Can this problem be reduced to Set Cover or Maximum Coverage?










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    I have encountered a problem similar to Set Cover (and Maximum Coverage):



    We have several sets in a universe with $N$ elements. What is the maximum number of sets so that the number of elements found in these sets is not greater than $frac{N}{2}$.



    Can this problem be reduced to Set Cover or Maximum Coverage?










    share|cite|improve this question



























      1












      1








      1







      I have encountered a problem similar to Set Cover (and Maximum Coverage):



      We have several sets in a universe with $N$ elements. What is the maximum number of sets so that the number of elements found in these sets is not greater than $frac{N}{2}$.



      Can this problem be reduced to Set Cover or Maximum Coverage?










      share|cite|improve this question















      I have encountered a problem similar to Set Cover (and Maximum Coverage):



      We have several sets in a universe with $N$ elements. What is the maximum number of sets so that the number of elements found in these sets is not greater than $frac{N}{2}$.



      Can this problem be reduced to Set Cover or Maximum Coverage?







      computational-complexity np-complete






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      share|cite|improve this question













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      edited yesterday

























      asked Nov 28 '12 at 22:38









      manix

      83




      83






















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          Yes. The above problem can be reduced to a generalization of the Maximum Coverage Problem, called Budgeted Maximum Coverage.



          Using the terminology of wiki page, select the weight of each object $e_j =1$ and cost $C(S_i) = |S_i|$, the size of $S_i$. Select the budget to be $frac{N}{2}$. Then your problem is exactly equal to solving the given problem.



          See the wiki page and reference within. Hope it helps.






          share|cite|improve this answer





















          • This seems right. I am not sure about C(Si)=|Si|. The same elements can be on different sets, so the cost varies.
            – manix
            Nov 28 '12 at 23:25











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          Yes. The above problem can be reduced to a generalization of the Maximum Coverage Problem, called Budgeted Maximum Coverage.



          Using the terminology of wiki page, select the weight of each object $e_j =1$ and cost $C(S_i) = |S_i|$, the size of $S_i$. Select the budget to be $frac{N}{2}$. Then your problem is exactly equal to solving the given problem.



          See the wiki page and reference within. Hope it helps.






          share|cite|improve this answer





















          • This seems right. I am not sure about C(Si)=|Si|. The same elements can be on different sets, so the cost varies.
            – manix
            Nov 28 '12 at 23:25
















          0














          Yes. The above problem can be reduced to a generalization of the Maximum Coverage Problem, called Budgeted Maximum Coverage.



          Using the terminology of wiki page, select the weight of each object $e_j =1$ and cost $C(S_i) = |S_i|$, the size of $S_i$. Select the budget to be $frac{N}{2}$. Then your problem is exactly equal to solving the given problem.



          See the wiki page and reference within. Hope it helps.






          share|cite|improve this answer





















          • This seems right. I am not sure about C(Si)=|Si|. The same elements can be on different sets, so the cost varies.
            – manix
            Nov 28 '12 at 23:25














          0












          0








          0






          Yes. The above problem can be reduced to a generalization of the Maximum Coverage Problem, called Budgeted Maximum Coverage.



          Using the terminology of wiki page, select the weight of each object $e_j =1$ and cost $C(S_i) = |S_i|$, the size of $S_i$. Select the budget to be $frac{N}{2}$. Then your problem is exactly equal to solving the given problem.



          See the wiki page and reference within. Hope it helps.






          share|cite|improve this answer












          Yes. The above problem can be reduced to a generalization of the Maximum Coverage Problem, called Budgeted Maximum Coverage.



          Using the terminology of wiki page, select the weight of each object $e_j =1$ and cost $C(S_i) = |S_i|$, the size of $S_i$. Select the budget to be $frac{N}{2}$. Then your problem is exactly equal to solving the given problem.



          See the wiki page and reference within. Hope it helps.







          share|cite|improve this answer












          share|cite|improve this answer



          share|cite|improve this answer










          answered Nov 28 '12 at 22:53









          dexter04

          1,6701027




          1,6701027












          • This seems right. I am not sure about C(Si)=|Si|. The same elements can be on different sets, so the cost varies.
            – manix
            Nov 28 '12 at 23:25


















          • This seems right. I am not sure about C(Si)=|Si|. The same elements can be on different sets, so the cost varies.
            – manix
            Nov 28 '12 at 23:25
















          This seems right. I am not sure about C(Si)=|Si|. The same elements can be on different sets, so the cost varies.
          – manix
          Nov 28 '12 at 23:25




          This seems right. I am not sure about C(Si)=|Si|. The same elements can be on different sets, so the cost varies.
          – manix
          Nov 28 '12 at 23:25


















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