Tag: programming

Counting Possible Passwords

Tags: dynamic-programming, programming

Published on Saturday, February 25th, 2017

Jack showed “the rules for password naming” in a website to me. Here’s an excerpt:

  1. The password must be exactly 8 characters long.
  2. It must contain at least one letter, one number, and one of the following special characters.
  3. The only special characters allowed are: @ # $
  4. A special chaacter must not be located in the first or last position.
  5. Two of the same characters sitting next to each other are considered to be a “set.” No “sets” are allowed. Example: rr, tt
  6. Avoid using names, such as your name, user ID, or the name of your company or employer.
  7. Other words that cannot be used are Texas, child, and the months of the year.
  8. A new password cannot be too similar to the previous password.

    • Example: previous password - abc#1234; unacceptable new password - acb$1243
    • Characters in the first, second, and third positions cannot be identical. (abc*****)
    • Characters in the second, third, and fourth positions cannot be identical. (*bc#****)
    • Characters in the sixth, seventh, and eighth positions cannot be identical. (*****234)
  9. A password can be changed voluntarily (no Help Desk assistance needed) once in a 15-day period. If needed, the Help Desk can reset the password at any time.
  10. The previous 8 passwords cannot be reused.

One way to create a password is creative spelling and substitution. Examples:

  1. phuny#2s
  2. fish#1ng
  3. t0pph@ts
  4. run$4you
  5. ba#3ries

I’m terrified.


Tags: dynamic-programming, competition, programming, lemmings

Published on Tuesday, December 27th, 2016

Wandering around in Wikipedia yesterday, I found this article: Lemmings. Though I never play this game before, I have played its open-source clone, Pingus, which is really enjoyable. This post is written to pay tribute to this wonderful game.