시간 제한메모리 제한제출정답맞힌 사람정답 비율
1 초 128 MB247834520298923.983%

문제

상근이와 친구들은 오스트레일리아로 여행을 떠났다. 상근이와 친구들은 총 M명이고, 지금 공항에서 한 줄로 서서 입국심사를 기다리고 있다. 입국심사대는 총 N개가 있다. 각 입국심사관이 심사를 하는데 걸리는 시간은 사람마다 모두 다르다. k번 심사대에 앉아있는 심사관이 한 명을 심사를 하는데 드는 시간은 Tk이다.

가장 처음에 모든 심사대는 비어있고, 심사를 할 준비를 모두 끝냈다. 상근이와 친구들은 비행기 하나를 전세내고 놀러갔기 때문에, 지금 심사를 기다리고 있는 사람은 모두 상근이와 친구들이다. 한 심사대에서는 한 번에 한 사람만 심사를 할 수 있다. 가장 앞에 서 있는 사람은 비어있는 심사대가 보이면 거기로 가서 심사를 받을 수 있다. 하지만 항상 이동을 해야 하는 것은 아니다. 더 빠른 심사대의 심사가 끝나길 기다린 다음에 그 곳으로 가서 심사를 받아도 된다.

상근이와 친구들은 모두 컴퓨터 공학과 학생이기 때문에, 어떻게 심사를 받으면 모든 사람이 심사를 받는데 걸리는 시간이 최소가 될지 궁금해졌다.

예를 들어, 두 심사대가 있고, 심사를 하는데 걸리는 시간이 각각 7초와 10초라고 하자. 줄에 서 있는 사람이 6명이라면, 가장 첫 두 사람은 즉시 심사를 받으러 가게 된다. 7초가 되었을 때, 첫 번째 심사대는 비어있게 되고, 세 번째 사람이 그곳으로 이동해서 심사를 받으면 된다. 10초가 되는 순간, 네 번째 사람이 이곳으로 이동해서 심사를 받으면 되고, 14초가 되었을 때는 다섯 번째 사람이 첫 번째 심사대로 이동해서 심사를 받으면 된다. 20초가 되었을 때, 두 번째 심사대가 비어있게 된다. 하지만, 여섯 번째 사람이 그 곳으로 이동하지 않고, 1초를 더 기다린 다음에 첫 번째 심사대로 이동해서 심사를 받으면, 모든 사람이 심사를 받는데 걸리는 시간이 28초가 된다. 만약, 마지막 사람이 1초를 더 기다리지않고, 첫 번째 심사대로 이동하지 않았다면, 모든 사람이 심사를 받는데 걸리는 시간이 30초가 되게 된다.

상근이와 친구들이 심사를 받는데 걸리는 시간의 최솟값을 구하는 프로그램을 작성하시오.

입력

첫째 줄에 N과 M이 주어진다. (1 ≤ N ≤ 100,000, 1 ≤ M ≤ 1,000,000,000)

다음 N개 줄에는 각 심사대에서 심사를 하는데 걸리는 시간인 Tk가 주어진다. (1 ≤ Tk ≤ 109)

출력

첫째 줄에 상근이와 친구들이 심사를 마치는데 걸리는 시간의 최솟값을 출력한다.

예제 입력 1

2 6
7
10

예제 출력 1

28

예제 입력 2

7 10
3
8
3
6
9
2
4

예제 출력 2

8
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(1 &le; N &le; 100,000, 1 &le; M &le; 1,000,000,000)<\/p>\r\n\r\n<p>\ub2e4\uc74c N\uac1c \uc904\uc5d0\ub294 \uac01 \uc2ec\uc0ac\ub300\uc5d0\uc11c \uc2ec\uc0ac\ub97c \ud558\ub294\ub370 \uac78\ub9ac\ub294 \uc2dc\uac04\uc778 T<sub>k<\/sub>\uac00 \uc8fc\uc5b4\uc9c4\ub2e4. (1 &le; T<sub>k<\/sub> &le; 10<sup>9<\/sup>)<\/p>\r\n","output":"<p>\uccab\uc9f8 \uc904\uc5d0 \uc0c1\uadfc\uc774\uc640 \uce5c\uad6c\ub4e4\uc774 \uc2ec\uc0ac\ub97c \ub9c8\uce58\ub294\ub370 \uac78\ub9ac\ub294 \uc2dc\uac04\uc758 \ucd5c\uc19f\uac12\uc744 \ucd9c\ub825\ud55c\ub2e4. <\/p>\r\n","hint":"","original":"0","html_title":"0","problem_lang_tcode":"Korean"},{"problem_id":"3079","problem_lang":"1","title":"AERODROM","description":"<p>The Croatian delegation, consisting of M people, is travelling to IOI 2013 in Australia. They are currently waiting in a queue for check-in at the airport. There are N check-in desks open. Some officials work more efficiently than others, so the desks operate at different speeds. At the k-th desk, T<sub>k<\/sub> seconds are required to finish check-in of a single passenger, and members of our delegation happen to know the exact numbers.<\/p>\r\n\r\n<p>In the beginning, all desks are ready to accept the next passenger, and the delegation members are the only people in the queue. A person can only occupy (start check-in at) an available desk when all people in front of that person in the queue have left the queue (started, not necessarily finished, check-in) already. At that moment, the person can immediately occupy an available desk (if there is one), but can also choose to wait for another (faster) desk to become available. Our delegation members, being computer science geeks, make this decision in such a way that the moment when all of them have finished check-in is as soon as possible. Your task is finding that moment in time.<\/p>\r\n\r\n<p>Let us describe the scenario from the first example below. There are two desks, with processing times of 7 and 10 seconds, respectively. Out of the six people in the delegation, the first two immediately occupy the two desks. At time 7, the first desk is freed, and the third person occupies it. At time 10, the fourth person occupies the second desk. At time 14, the fifth person occupies the first desk. At time 20, the second desk is freed again, but the sixth person decides to wait another second (time 21) for the first desk to become available, and then occupy it. This way, the check-in is completed by time 28. 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출처

Contest > Croatian Open Competition in Informatics > COCI 2012/2013 > Contest #3 4번