How do I optimize my Python code for balancing a centrifuge with a given input size?











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So, the problem is, given an input N as the size of a centrifuge, I need to find out the number of balanced configurations. The full description is here.




Centrifuge is a piece of equipment that puts multiple test tubes in rotation at very high speeds. It consists of a cylindrical rotor with holes situated evenly along the circumference of the rotor.
Because the device is operating at high speeds, the center of mass of all tubes must coincide with the center of the rotor. We assume all tubes have the same mass.



For the sake of simplicity, we also assume that tubes are point masses, fixed firmly to the rotor. All at the same distance from the center. You may safely assume the (x,y) coordinates of tube k are $Rsin a, Rcos a$, where $a = 2pifrac{k}{n}$



The problem is: Given a centrifuge with N holes and K tubes, is it possible to balance it?



example 1: given N = 6 possible values for K are 2,3,4,6.



example 2: given N = 12, it is possible to balance 5 tubes: put 3 evenly dispersed (every 4th hole), then find a pair of opposite unoccupied holes and insert remaining 2 tubes there.



example 3: given N = 10, it is impossible to balance 7 tubes: put 5 evenly dispersed, and there's no opposite unoccupied holes left!




This is my code:



import numpy as np

N=int(input())
angle = 2*np.pi/N
z = complex(np.cos(angle), np.sin(angle))


import itertools
combs =
lst = range(1,N)
for i in range(2, N-1):
combs.append(i)
els = [list(x) for x in itertools.combinations(lst, i)]
combs.append(els)


count=1
lis =
while count<=len(combs):
for a in range(len(combs[count])):
s=0
for b in range(len(combs[count][a])):
s+=z**combs[count][a][b]
if abs(s)<1e-10:
lis.append(combs[count][a])
count+=2


lengths =
for i in lis:
if len(i) not in lengths:
lengths.append(len(i))

print(len(lengths)+1)


The code works fine, but slows down after input size of above 20, and is practically unusable after the input grows to 50 or above, due to the for loops. How do I optimize it?










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Kristada673 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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    So, the problem is, given an input N as the size of a centrifuge, I need to find out the number of balanced configurations. The full description is here.




    Centrifuge is a piece of equipment that puts multiple test tubes in rotation at very high speeds. It consists of a cylindrical rotor with holes situated evenly along the circumference of the rotor.
    Because the device is operating at high speeds, the center of mass of all tubes must coincide with the center of the rotor. We assume all tubes have the same mass.



    For the sake of simplicity, we also assume that tubes are point masses, fixed firmly to the rotor. All at the same distance from the center. You may safely assume the (x,y) coordinates of tube k are $Rsin a, Rcos a$, where $a = 2pifrac{k}{n}$



    The problem is: Given a centrifuge with N holes and K tubes, is it possible to balance it?



    example 1: given N = 6 possible values for K are 2,3,4,6.



    example 2: given N = 12, it is possible to balance 5 tubes: put 3 evenly dispersed (every 4th hole), then find a pair of opposite unoccupied holes and insert remaining 2 tubes there.



    example 3: given N = 10, it is impossible to balance 7 tubes: put 5 evenly dispersed, and there's no opposite unoccupied holes left!




    This is my code:



    import numpy as np

    N=int(input())
    angle = 2*np.pi/N
    z = complex(np.cos(angle), np.sin(angle))


    import itertools
    combs =
    lst = range(1,N)
    for i in range(2, N-1):
    combs.append(i)
    els = [list(x) for x in itertools.combinations(lst, i)]
    combs.append(els)


    count=1
    lis =
    while count<=len(combs):
    for a in range(len(combs[count])):
    s=0
    for b in range(len(combs[count][a])):
    s+=z**combs[count][a][b]
    if abs(s)<1e-10:
    lis.append(combs[count][a])
    count+=2


    lengths =
    for i in lis:
    if len(i) not in lengths:
    lengths.append(len(i))

    print(len(lengths)+1)


    The code works fine, but slows down after input size of above 20, and is practically unusable after the input grows to 50 or above, due to the for loops. How do I optimize it?










    share|improve this question









    New contributor




    Kristada673 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
    Check out our Code of Conduct.






















      up vote
      0
      down vote

      favorite









      up vote
      0
      down vote

      favorite











      So, the problem is, given an input N as the size of a centrifuge, I need to find out the number of balanced configurations. The full description is here.




      Centrifuge is a piece of equipment that puts multiple test tubes in rotation at very high speeds. It consists of a cylindrical rotor with holes situated evenly along the circumference of the rotor.
      Because the device is operating at high speeds, the center of mass of all tubes must coincide with the center of the rotor. We assume all tubes have the same mass.



      For the sake of simplicity, we also assume that tubes are point masses, fixed firmly to the rotor. All at the same distance from the center. You may safely assume the (x,y) coordinates of tube k are $Rsin a, Rcos a$, where $a = 2pifrac{k}{n}$



      The problem is: Given a centrifuge with N holes and K tubes, is it possible to balance it?



      example 1: given N = 6 possible values for K are 2,3,4,6.



      example 2: given N = 12, it is possible to balance 5 tubes: put 3 evenly dispersed (every 4th hole), then find a pair of opposite unoccupied holes and insert remaining 2 tubes there.



      example 3: given N = 10, it is impossible to balance 7 tubes: put 5 evenly dispersed, and there's no opposite unoccupied holes left!




      This is my code:



      import numpy as np

      N=int(input())
      angle = 2*np.pi/N
      z = complex(np.cos(angle), np.sin(angle))


      import itertools
      combs =
      lst = range(1,N)
      for i in range(2, N-1):
      combs.append(i)
      els = [list(x) for x in itertools.combinations(lst, i)]
      combs.append(els)


      count=1
      lis =
      while count<=len(combs):
      for a in range(len(combs[count])):
      s=0
      for b in range(len(combs[count][a])):
      s+=z**combs[count][a][b]
      if abs(s)<1e-10:
      lis.append(combs[count][a])
      count+=2


      lengths =
      for i in lis:
      if len(i) not in lengths:
      lengths.append(len(i))

      print(len(lengths)+1)


      The code works fine, but slows down after input size of above 20, and is practically unusable after the input grows to 50 or above, due to the for loops. How do I optimize it?










      share|improve this question









      New contributor




      Kristada673 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.











      So, the problem is, given an input N as the size of a centrifuge, I need to find out the number of balanced configurations. The full description is here.




      Centrifuge is a piece of equipment that puts multiple test tubes in rotation at very high speeds. It consists of a cylindrical rotor with holes situated evenly along the circumference of the rotor.
      Because the device is operating at high speeds, the center of mass of all tubes must coincide with the center of the rotor. We assume all tubes have the same mass.



      For the sake of simplicity, we also assume that tubes are point masses, fixed firmly to the rotor. All at the same distance from the center. You may safely assume the (x,y) coordinates of tube k are $Rsin a, Rcos a$, where $a = 2pifrac{k}{n}$



      The problem is: Given a centrifuge with N holes and K tubes, is it possible to balance it?



      example 1: given N = 6 possible values for K are 2,3,4,6.



      example 2: given N = 12, it is possible to balance 5 tubes: put 3 evenly dispersed (every 4th hole), then find a pair of opposite unoccupied holes and insert remaining 2 tubes there.



      example 3: given N = 10, it is impossible to balance 7 tubes: put 5 evenly dispersed, and there's no opposite unoccupied holes left!




      This is my code:



      import numpy as np

      N=int(input())
      angle = 2*np.pi/N
      z = complex(np.cos(angle), np.sin(angle))


      import itertools
      combs =
      lst = range(1,N)
      for i in range(2, N-1):
      combs.append(i)
      els = [list(x) for x in itertools.combinations(lst, i)]
      combs.append(els)


      count=1
      lis =
      while count<=len(combs):
      for a in range(len(combs[count])):
      s=0
      for b in range(len(combs[count][a])):
      s+=z**combs[count][a][b]
      if abs(s)<1e-10:
      lis.append(combs[count][a])
      count+=2


      lengths =
      for i in lis:
      if len(i) not in lengths:
      lengths.append(len(i))

      print(len(lengths)+1)


      The code works fine, but slows down after input size of above 20, and is practically unusable after the input grows to 50 or above, due to the for loops. How do I optimize it?







      python performance python-3.x programming-challenge






      share|improve this question









      New contributor




      Kristada673 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.











      share|improve this question









      New contributor




      Kristada673 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.









      share|improve this question




      share|improve this question








      edited 4 mins ago









      vnp

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      38.4k13096






      New contributor




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      asked 18 mins ago









      Kristada673

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      Kristada673 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.





      New contributor





      Kristada673 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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      Check out our Code of Conduct.



























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