Talk:Digital root

task change?

The task description seems to have changed. It's not entirely clear whether the task has changed.

Based on the initial task description and the initial text on the wikipedia page, this appeared to be a "sum the digits, repeat" task.

However, it now looks like a "mathematically equivalent to sum the digits" task. In other words, divide by 9 and find the remainder.

However, it's also possible (based on the language referred to on the wikipedia page) that we need an equality operation which compares its results modulo 9 (so that 9 equals 0).

That said, it's probably bad practice to define a task by reference to wikipedia. A wikipedia page can easily describe multiple distinct implementations and is expected to change over time.

So... I think that this task should be rephrased to clearly state what the goals are. The wikipedia references should be just references, and the task statement should be clear without them. --Rdm 13:42, 23 July 2012 (UTC)

The new interpretation of WP text is incorrect. Digital root of 9 is 9, while WP text only says it acts "as a kind of zero", not literally defining it to zero. Read the text carefully. Defs given in opening text and in the "Formal definition" section down were consistent, making digital roots of multiples of nines to be 9. --Ledrug 13:54, 23 July 2012 (UTC)

Author Name?

Two or more C++ entries contain the name of their author. Is this OK and good?

Only if it's taken from another source with permission and credit needs to be given. Otherwise we can use the wiki history to determine who authored what parts of the examples. --Mwn3d 14:55, 1 August 2012 (UTC)