CODEWITHSUNDEEP
pythonlistcollatz
user2956514
user2956514

Reputation: 39

How can I put these numbers in list?

So I have this Collatz conjecture assignment. Basically I have to write a program to which I give number and it will calculate Collatz conjecture for it. Here is my problem though: the number that will come out will be written like this :

12
6
3
10
5
16
8
4
2
1

When they should be in list like this [12, 6, 3, 10, 5, 16, 8, 4, 2, 1].

And here is my code:

n = int(input("The number is: "))
while n != 1:
  print(n)
  if n % 2 == 0:
     n //= 2
  else:
     n = n * 3 + 1
print(1)

Upvotes: 1

Views: 13581

Answers (3)

Aziz Harrington
Aziz Harrington

Reputation: 1

A recursive version, just for fun:

number = int(input("the number is: "))

def collatz(n):
    if n == 1:
        return [n]
    elif n % 2 == 0:
        return [n] + collatz(n/2)
    else:
        return [n] + collatz((3*n)+1)

print collatz(number)

Upvotes: 0

Lennart Regebro
Lennart Regebro

Reputation: 172309

This is also an option. A silly one, but still:

n = int(input("The number is: "))
print('[', end='')
while n != 1:
  print(n, end=', ')
  if n % 2 == 0:
     n //= 2
  else:
     n = n * 3 + 1
print('1]')

Upvotes: 1

thefourtheye
thefourtheye

Reputation: 239573

You have to store the numbers in a list

result = []
while n != 1: 
      result.append(n) 
      if n % 2 == 0:
          n //= 2
      else:
          n = n * 3 + 1
result.append(n) 

print result

Upvotes: 2

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