Cualquier bug encontrado o mejora que se pueda hacer al código, se agradecen los comentarios!
Problema 1.6.1: The 3n + 1 Problem
Consider the following algorithm to generate a sequence of numbers. Start with an
integer n. If n is even, divide by 2. If n is odd, multiply by 3 and add 1. Repeat this
process with the new value of n, terminating when n = 1. For example, the following
sequence of numbers will be generated for n = 22:
22 11 34 17 52 26 13 40 20 10 5 16 8 4 2 1
It is conjectured (but not yet proven) that this algorithm will terminate at n = 1 for
every integer n. Still, the conjecture holds for all integers up to at least 1, 000, 000.
For an input n, the cycle-length of n is the number of numbers generated up to and
including the 1. In the example above, the cycle length of 22 is 16. Given any two
numbers i and j, you are to determine the maximum cycle length over all numbers
between i and j, including both endpoints.
The input will consist of a series of pairs of integers i and j, one pair of integers per
line. All integers will be less than 1,000,000 and greater than 0.
For each pair of input integers i and j, output i, j in the same order in which they
appeared in the input and then the maximum cycle length for integers between and
including i and j. These three numbers should be separated by one space, with all three
numbers on one line and with one line of output for each line of input.
1 10 20
100 200 125
201 210 89
900 1000 174
def main(): f = open('input161', 'r') input = f.readlines() for line in input: n, n2 = line.replace('\n', '').split(' ') n, n2 = int(n), int(n2) maxCycle = 0 for i in range((n2-n) + 1): l =  num = n + i l.append(num) while num != 1: num = num/2 if num % 2 == 0 else num*3+1 l.append(num) if len(l) > maxCycle: maxCycle = len(l) print n, n2, maxCycle if __name__ == '__main__': main()