#P14679. [ICPC 2025 Seoul R] Triple Fairness
[ICPC 2025 Seoul R] Triple Fairness
题目描述
This problem adopts exactly the same definition of Fair Problemset as Problem H, "Fair Problemset".
ICPC is a team competition. Each team has three members. At the beginning of a contest, most teams divide the problem evenly. They use one of two common methods to distribute problems:
- Sequential Distribution: Each member takes a contiguous block of problems from the set of problems. Specifically, the first member takes problems , the second member takes problems , and the third member takes problems .
- Jump Distribution: Each member takes problems with indices that have the same remainder when divided by 3 from the set of problems. Specifically, the first member takes problems , the second member takes problems , and the third member takes problems .
The ICPC Seoul Regional Contest Scientific Committee must prepare a problemset consisting of problems. The difficulty of each problem is represented by an integer from 1 to , inclusive. For each difficulty, there are exactly three problems with that difficulty. Thus, the arrangement of difficulties in the problemset can be viewed as a difficulty sequence of length containing three problems of each of the difficulty levels.
To prevent any advantage or disadvantage for a team based on their chosen problem distribution method, the ICPC Seoul Regional Contest Scientific Committee has defined a standard called a Fair Problemset. A difficulty sequence of length is called a Fair Problemset if it satisfies both of the following conditions:
- Sequential Distribution Fairness: When using Sequential Distribution, for every difficulty level (), each of the three members receives exactly one problem with difficulty .
- Jump Distribution Fairness: When using Jump Distribution, for every difficulty level (), each of the three members receives exactly one problem with difficulty .
In other words, regardless of which of the two methods is chosen, each team member must be assigned exactly one problem for each difficulty level from 1 to , inclusive.
Given a positive integer , write a program to find any Fair Problemset sequence of length .
输入格式
Your program is to read from standard input. The input consists of exactly one line. The line contains an integer (); is not divisible by 3. It can be shown that for every valid input, there exists at least one Fair Problemset sequence of length .
输出格式
Your program is to write to standard output. Print exactly one line consisting of space-separated positive integers, representing a Fair Problemset sequence of length . Any valid Fair Problemset sequence of length will be accepted.
2
1 2 1 2 1 2
4
1 2 3 4 1 4 2 3 1 3 4 2