Hacker News Reader

Comment by harshalizee | Hacker News Reader

Looks like I'd fail your pre-screen test. What's the "mathematical" solution if you're not allowed to convert strings to ints? Ascii math?

View on HN

I think it just means taking the input as an integer and then separating out the “ones place”and “tens place” using integer division and modulo operator. E.g.,

  ones = number % 10

  tens = number // 10

  do_print = (ones + tens) == 10

That's what my solution after the parsing would be.

OP mentioned reading from a file, which you would only be able to use after string conversion to ints.

Maybe they didin't calculated the digits, like this:

if toInt(number) % 10 != 0

  print number

else

  print number + "(" + number[0] + "," + number[1] + ")"

Yes. This is the mathematical solution.

Not quite sure, and I'm not quite sure I care either. ;-)

However for any multiple of 9, the digits will add up to a multiple of 9. So you're looking for numbers in [ (n+2)*9 + 1 for n in range(9) ]

I think hahamrfunnyguy must have meant "convert the numbers to strings" - that's the only way I can make sense of it. quiz.txt must contain code, not sample data.

Yes, quiz.txt was the start of a C# program with a main method and a function that was called to do the work asked.

The common string based solution was to use a for loop, convert the counter to a string, parse the digits converting each one to a an integer and performing the calculation.

The exercise was given in C# so candidates just use string interpolation to output the result

Reply on news.ycombinator.com