Crooked Dealing
시간 제한2초메모리 제한512 MB
서로 다른 값을 h개씩 담은 손패를 최대한 많이 만들고, 그중 하나의 배분 결과를 출력한다.
문제
This week you started a flashy new job in Leeds as a poker dealer. Your task will be to hand out the cards for games. The base pay is not particularly good, but you found out that you can earn a lot from tips if you deal the cards well.
The most generous customers prefer that their opponents at the table don’t receive any pairs of cards with the same number; so to keep them happy you will make sure this never happens.
You already know the numbers on every card in the pile , and the number of cards any player must have in their hand. Find how many hands you can make at once without introducing a pair.
Figure C.1: Illustration of a solution to Sample Input 2.
입력
The input consists of:
- A line with two integers n and h (1 ≤ h ≤ n ≤ 106), the number of cards in the pile, and the number of cards in a hand.
- A line with n integers v1, . . . , vn (1 ≤ vi ≤ 106 for all i), the numbers on the cards in no particular order.
출력
If it is not possible to make any hands at all without introducing a pair, output impossible.
Otherwise, output k lines (where k is the maximum possible number of players) each containing h numbers from the input. You may not use any number any more times than it appears in v.
If there are multiple answers with a maximum value of k, you may output any one of them.