10211 - Divisibility Testing! Wow!

[10153EN]

I have tired this problem but got wrong answer...

Could anyone tell me what's the base of the second input of each input set?

e.g. if the input is 16 20
then it means the base is 16
but the 20 means a decimal 20 or 20 of base 16?

Thx in advance =)

[Adrian Kuegel]

I havn't tried this problem yet, but I am absolutely sure that the second number is a decimal number, because in the description of the problem there is no definition how to write for example 97 in base 100, therefore the problem wouldn't be solvable.

[Per]

Could someone confirm or refute these outputs?

Input:

Code: Select all

439 2918
27 12
3 13
3141 592
10 6

Output:

Code: Select all

Add all 1458
Alternate 729 change sign

condition not found.

Add all 3

Add all 36

condition not found.

[Andrey Mokhov]

Hello!

My AC program produced this:

Code: Select all

Alternate 729 change sign

condition not found.

Add all 3

Add all 36

condition not found.

According to the problem statement Add all 1458 is illegal.

Have AC!
Andrey.

[Per]

Thanks Andrey!

I had misunderstood the output format. Also I had another mistake, in handling cases such as "7 2", but now I'm AC. Thanks!

[Wei-Ming Chen]

Hello, what are the outputs of

Code: Select all

10 6
5 2

Thanks

[rio]

My AC code outputs:

Code: Select all

condition not found.

Add all 1
Alternate 1 change sign

----
Rio

[Wei-Ming Chen]

Code: Select all

5 2

why the answer is

Code: Select all

Add all 1 
Alternate 1 change sign

not

Code: Select all

Add all 1

[rio]

Because:

Code: Select all

Sum of all digits is even(odd)  <--> Sum of all digits with alternative signs is even(odd)

----
RIo

[Wei-Ming Chen]

Thanks rio

you help me again and again..

[forthright48]

Really interesting problem. I knew about the divisibility rules before, but to solve the problem, I had to finally understand the proofs formally.