mirror of
https://github.com/TheAlgorithms/Python.git
synced 2024-12-01 00:41:09 +00:00
16 lines
695 B
Python
16 lines
695 B
Python
def collatz_sequence(n):
|
|
"""Collatz conjecture: start with any positive integer n.Next termis obtained from the previous term as follows:
|
|
if the previous term is even, the next term is one half the previous term.
|
|
If the previous term is odd, the next term is 3 times the previous term plus 1.
|
|
The conjecture states the sequence will always reach 1 regaardess of starting n."""
|
|
sequence = [n]
|
|
while n != 1:
|
|
if n % 2 == 0:# even
|
|
n //= 2
|
|
else:
|
|
n = 3*n +1
|
|
sequence.append(n)
|
|
return sequence
|
|
|
|
answer = max([(len(collatz_sequence(i)), i) for i in range(1,1000000)])
|
|
print("Longest Collatz sequence under one million is %d with length %d" % (answer[1],answer[0])) |