Hailstone Numbers

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Points: 3
Time limit: 2.0s
Memory limit: 64M

Problem type

Pick a positive integer n. If it is odd, multiply it by three and then add one. If n is even, divide it by two. The positive integer obtained is the new n, and this is repeated until the number becomes 1. Given the value of n, with 1 \le n< 2^{31}, determine the number of operations before n becomes 1.

Sample Input


Sample Output



n will become 10, 5, 16, 8, 4, 2, then 1, which is a total of 7 operations.


  • 6
    jason6  commented on Oct. 27, 2018, 6:06 p.m.

    Collatz Conjecture!

    • 1
      SeanJxie  commented on Dec. 18, 2019, 10:04 a.m.

      Someone has been watching NumberPhile!

  • 4
    aeternalis1  commented on Nov. 18, 2017, 10:14 a.m. edited

    For the full explanation:

    1. Stop asking for help in comments.

    2. Go to https://slack.dmoj.ca/ and ask for help in the #help channel.