Editorial for An Animal Contest 6 P1 - Workout Routine

Remember to use this editorial only when stuck, and not to copy-paste code from it. Please be respectful to the problem author and editorialist.
Submitting an official solution before solving the problem yourself is a bannable offence.

Author: dxke02

Hint

The answer is never $-1$ ~-1~.

Subtask 1

The intended solution for this subtask is to output the sequence $K, 2K, 3K, \dots, NK$ ~K, 2K, 3K, \dots, NK~. Since all terms are divisible by $K$ ~K~, their sum is also divisible by $K$ ~K~.

Subtask 2

One possible answer is to first generate the sequence $1, 2, \dots, N-1$ ~1, 2, \dots, N-1~, then fill in the last element with any element that makes the sum divisible by $K$ ~K~.

Comments

0

Humanthe2nd commented on Oct. 19, 2024, 2:30 a.m.

As as alternative I used, $K$ ~K~ could be doubled until it is strictly greater than $N$ ~N~ (as multiples of $K$ ~K~ are divisible by $K$ ~K~). Then for each integer $X$ ~X~ in $[1,N/2]$ ~[1,N/2]~, $X$ ~X~ and $K-X$ ~K-X~ could be used. In addition if $N$ ~N~ is odd then $K$ ~K~ itself could be added.