Gearing_Up_For_Destruction

gistfile1.txt

from fractions import Fraction  
def answer(pegs):
  arrLength = len(pegs)
  if ((not pegs) or arrLength == 1):
    return [-1,-1]
            
  even = True if (arrLength % 2 == 0) else False
  sum = (- pegs[0] + pegs[arrLength - 1]) if even else (- pegs[0] - pegs[arrLength -1])
        
  if (arrLength > 2):
    for index in xrange(1, arrLength-1):
      sum += 2 * (-1)**(index+1) * pegs[index]
    
  FirstGearRadius = Fraction(2 * (float(sum)/3 if even else sum)).limit_denominator()
  #now that we have the radius of the first gear, we should again check the input array of pegs to verify that
  #the pegs radius' is atleast 1.
        
  currentRadius = FirstGearRadius
  for index in xrange(0, arrLength-2):
    CenterDistance = pegs[index+1] - pegs[index]
    NextRadius = CenterDistance - currentRadius
    if (currentRadius < 1 or NextRadius < 1):
      return [-1,-1]
    else:
      currentRadius = NextRadius
         
  return [FirstGearRadius.numerator, FirstGearRadius.denominator]