Complexity for a reccurence relation











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If $ T(n) = sqrt{2n}T(sqrt{2n} )+ {n ^ 2} $ , what is complexity of T(n)?



Well, I let $ n = {2 ^ k} $ , $ y(k) = frac{T({2 ^ k} )}{4 ^ k} $ and I tried to resolve this recurrence by iterations methods, but I saw that it not works here. How I can find the complexity for this recurrence?










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    up vote
    0
    down vote

    favorite












    If $ T(n) = sqrt{2n}T(sqrt{2n} )+ {n ^ 2} $ , what is complexity of T(n)?



    Well, I let $ n = {2 ^ k} $ , $ y(k) = frac{T({2 ^ k} )}{4 ^ k} $ and I tried to resolve this recurrence by iterations methods, but I saw that it not works here. How I can find the complexity for this recurrence?










    share|cite|improve this question
























      up vote
      0
      down vote

      favorite









      up vote
      0
      down vote

      favorite











      If $ T(n) = sqrt{2n}T(sqrt{2n} )+ {n ^ 2} $ , what is complexity of T(n)?



      Well, I let $ n = {2 ^ k} $ , $ y(k) = frac{T({2 ^ k} )}{4 ^ k} $ and I tried to resolve this recurrence by iterations methods, but I saw that it not works here. How I can find the complexity for this recurrence?










      share|cite|improve this question













      If $ T(n) = sqrt{2n}T(sqrt{2n} )+ {n ^ 2} $ , what is complexity of T(n)?



      Well, I let $ n = {2 ^ k} $ , $ y(k) = frac{T({2 ^ k} )}{4 ^ k} $ and I tried to resolve this recurrence by iterations methods, but I saw that it not works here. How I can find the complexity for this recurrence?







      recurrence-relations






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      asked Nov 15 at 10:14









      Daniel

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      166






















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          Try substituting $n$ by $2^{k+1}$ and consider $S(k)=frac{T(2^{k+1})}{2^{k+1}}$ which is $T(n)/n$ and this in turn is equal to $2frac{T(sqrt{2n})}{sqrt{2n}} + n$. By observing that $sqrt{2n}=2^{frac{k}{2}+1}$ you reduce your recurrence to a simpler one $S(k) = 2S(frac{k}{2})+2^{k+1}$. This you might find easier to solve.






          share|cite|improve this answer





















          • Nice! It easier to solve now, thanks!
            – Daniel
            Nov 15 at 14:15











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          active

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          up vote
          1
          down vote



          accepted










          Try substituting $n$ by $2^{k+1}$ and consider $S(k)=frac{T(2^{k+1})}{2^{k+1}}$ which is $T(n)/n$ and this in turn is equal to $2frac{T(sqrt{2n})}{sqrt{2n}} + n$. By observing that $sqrt{2n}=2^{frac{k}{2}+1}$ you reduce your recurrence to a simpler one $S(k) = 2S(frac{k}{2})+2^{k+1}$. This you might find easier to solve.






          share|cite|improve this answer





















          • Nice! It easier to solve now, thanks!
            – Daniel
            Nov 15 at 14:15















          up vote
          1
          down vote



          accepted










          Try substituting $n$ by $2^{k+1}$ and consider $S(k)=frac{T(2^{k+1})}{2^{k+1}}$ which is $T(n)/n$ and this in turn is equal to $2frac{T(sqrt{2n})}{sqrt{2n}} + n$. By observing that $sqrt{2n}=2^{frac{k}{2}+1}$ you reduce your recurrence to a simpler one $S(k) = 2S(frac{k}{2})+2^{k+1}$. This you might find easier to solve.






          share|cite|improve this answer





















          • Nice! It easier to solve now, thanks!
            – Daniel
            Nov 15 at 14:15













          up vote
          1
          down vote



          accepted







          up vote
          1
          down vote



          accepted






          Try substituting $n$ by $2^{k+1}$ and consider $S(k)=frac{T(2^{k+1})}{2^{k+1}}$ which is $T(n)/n$ and this in turn is equal to $2frac{T(sqrt{2n})}{sqrt{2n}} + n$. By observing that $sqrt{2n}=2^{frac{k}{2}+1}$ you reduce your recurrence to a simpler one $S(k) = 2S(frac{k}{2})+2^{k+1}$. This you might find easier to solve.






          share|cite|improve this answer












          Try substituting $n$ by $2^{k+1}$ and consider $S(k)=frac{T(2^{k+1})}{2^{k+1}}$ which is $T(n)/n$ and this in turn is equal to $2frac{T(sqrt{2n})}{sqrt{2n}} + n$. By observing that $sqrt{2n}=2^{frac{k}{2}+1}$ you reduce your recurrence to a simpler one $S(k) = 2S(frac{k}{2})+2^{k+1}$. This you might find easier to solve.







          share|cite|improve this answer












          share|cite|improve this answer



          share|cite|improve this answer










          answered Nov 15 at 11:32









          Lacramioara

          32126




          32126












          • Nice! It easier to solve now, thanks!
            – Daniel
            Nov 15 at 14:15


















          • Nice! It easier to solve now, thanks!
            – Daniel
            Nov 15 at 14:15
















          Nice! It easier to solve now, thanks!
          – Daniel
          Nov 15 at 14:15




          Nice! It easier to solve now, thanks!
          – Daniel
          Nov 15 at 14:15


















           

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