3n+1

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Points: 3

Time limit: 1.0s

Memory limit: 16M

Problem type

Pick a positive integer $n$ $n$ . If it is odd, multiply it by three and then add one. Otherwise (if it is even), divide it by two. The positive integer obtained is the new $n$ $n$ , and this procedure is repeated.

It is believed that $n$ $n$ will eventually become $1$ $1$ (this is called the Collatz conjecture.) Computers have checked that any value of $n$ $n$ less than $10^{20}$ $10^{20}$ does, indeed, eventually become $1$ $1$ if this procedure is applied enough times.

You will be given the value of $n$ $n$ . Determine how many times this procedure must be applied before $n$ $n$ becomes $1$ $1$ .

Input Specification

The initial value of $n$ $n$ .

Output Specification

The number of operations we have to perform on $n$ $n$ before it becomes $1$ $1$ .

Constraints

Any value of $n$ $n$ , initial or intermediate, will be less than $2^{31}$ $2^{31}$ .

Sample Input

Copy

Sample Output

Copy

Explanation

$n$ $n$ will go through these steps:

$\displaystyle 7, 22, 11, 34, 17, 52, 26, 13, 40, 20, 10, 5, 16, 8, 4, 2, 1$ $7, 22, 11, 34, 17, 52, 26, 13, 40, 20, 10, 5, 16, 8, 4, 2, 1$

Comments

0

stanwww commented on Oct. 30, 2024, 12:46 p.m.

The input data has been set so any intermediate results will be less than 2^31 so n is only 35655. Can you also check if new test cases are needed?

6

OneYearOld commented on Oct. 28, 2020, 1:23 p.m. ← edited →

The test data is very weak. $0 < n < 35655$ $0 < n < 35655$ .

1

QooModa commented on May 10, 2022, 10:15 p.m.

Genuine question.

How do you check the test data?

It would help me solve other problems, I think...

Thanks!

0

Smug_Void commented on March 29, 2023, 3:20 p.m.

copy the input data and then just print it out

0

FlowerPollinator commented on Sept. 26, 2022, 11:06 p.m.

You don't, unless the problem originated from somewhere else