問題一覧 > 通常問題

No.59 Railway Journey

レベル : / AI推定難易度 : 1000 / 実行時間制限 : 1ケース 5.000秒 / メモリ制限 : 512 MB / 標準ジャッジ問題
タグ : (AC するまで非表示) / 解いたユーザー数 233
作問者 : nmnmnmnmnmnmnm
お気に入りにしたユーザー ProblemId : 98 / 自分の提出
問題文最終更新日: 2026-06-25 23:34:29
This statement was translated by AI (claude-opus-5-5, effort medium) and may contain errors or differ in nuance from the original. The original statement takes precedence. Back to the original
yukicoder contest 48 (順位表) の他の問題:

Problem Statement

A train travels from the departure station to the terminal station.
There are N intermediate stations along the way.
The train always stops at every intermediate station.
The train carries no luggage at all at the departure station.
At each intermediate station, it is determined that one piece of luggage is either loaded or unloaded.
Each piece of luggage has a weight W.
At each intermediate station, the weight of the luggage to load or unload is specified.
・If \(W\) is a positive number, a piece of luggage of weight \(|W|\) is loaded.
・If \(W\) is a negative number, a piece of luggage of weight \(|W|\) is unloaded.

There is one unusual rule here.

・If, before loading a piece of luggage, K or more pieces of luggage with weight greater than or equal to that luggage's weight are already on the train, that luggage cannot be loaded.

Because of this unusual rule, there are cases where luggage cannot be loaded.
If the rule is not violated, the luggage is always loaded.

It is also possible that, when unloading, no luggage of the specified weight is on the train.
In this case, since the specified luggage does not exist, there is no need to unload anything.
If luggage of the specified weight exists, exactly one piece is always unloaded.
How many pieces of luggage will ultimately be carried to the final station?

Input

\(N\,K\)
\(W_1\)
\(W_2\)
\(\dots\)
\(W_n\)

The number of intermediate stations \(N\) and the value \(K\) related to the rule are given.
\((1 \le N \le 100000)\) (\(N\) is a positive integer)
\((1 \le K \le 100000)\) (\(K\) is a positive integer)
The luggage weights \(W_i\) at the intermediate station reached i-th are given in order over N lines.
\(-1000000 \le W_i < 0、0< W_i \le 1000000\) (\(W_i\) is a non-zero integer)
A negative weight represents unloading luggage.

Output

Output on one line the number of pieces of luggage loaded on the train at the final station.
Don't forget the newline at the end.

Sample

Sample 1
Input
3 2
3
3
2
Output
2

There are 3 intermediate stations.
At the first 2 stations, one piece of luggage of weight 3 is loaded at each.
At the 3rd station, we want to load one piece of luggage of weight 2.
However, there are already 2 pieces of luggage of weight 2 or more.
By the rule, this luggage of weight 2 cannot be loaded.
Therefore, 2 pieces of luggage remain in the end.

Sample 2
Input
3 2
3
-3
2
Output
1

There are 3 intermediate stations.
At the 1st station, a piece of luggage of weight 3 is loaded.
At the 2nd station, a piece of luggage of weight 3 is unloaded.
At the 3rd station, a piece of luggage of weight 2 can be loaded.
Therefore, 1 piece of luggage remains in the end.

Sample 3
Input
5 1
5
-6
6
5
7
Output
3

There are 5 intermediate stations.
At the 1st station, a piece of luggage of weight 5 is loaded.
At the 2nd station, there is no luggage of weight 6, so no luggage is unloaded.
At the 3rd station, a piece of luggage of weight 6 is loaded.
At the 4th station, there is already at least 1 piece of luggage of weight 5 or more, so the luggage of weight 5 cannot be loaded.
At the 5th station, a piece of luggage of weight 7 is loaded.
Therefore, 3 pieces of luggage remain in the end.

Sample 4
Input
57 8 
697
-764
-97
-58
337
-216
-827
399
-764
753
-764
764
-307
-30
-137
764
-463
-124
-815
816
546
-487
764
-43
31
162
-189
-64
-473
-884
172
546
985
901
-319
-718
-495
764
546
172
425
-816
-645
135
128
-553
764
-409
-162
276
-262
770
-162
904
337
764
-816
Output
15

提出するには、Twitter 、GitHub、 Googleもしくは右上の雲マークをクリックしてアカウントを作成してください。