题库练习 Sleeping Schedule
← 上一题 下一题 →

A13307 | Sleeping Schedule

时间限制1s
内存限制256MB
通过 / 提交0/0

题目描述

Vova had a pretty weird sleeping schedule. There are $h$ hours in a day. Vova will sleep exactly $n$ times. The $i$ -th time he will sleep exactly after $a_i$ hours from the time he woke up. You can assume that Vova woke up exactly at the beginning of this story (the initial time is $0$ ). Each time Vova sleeps exactly one day (in other words, $h$ hours).

Vova thinks that the $i$ -th sleeping time is good if he starts to sleep between hours $l$ and $r$ inclusive.

Vova can control himself and before the $i$ -th time can choose between two options: go to sleep after $a_i$ hours or after $a_i - 1$ hours.

Your task is to say the maximum number of good sleeping times Vova can obtain if he acts optimally.

输入格式

The first line of the input contains four integers $n, h, l$ and $r$ ( $1 \le n \le 2000, 3 \le h \le 2000, 0 \le l \le r < h$ ) — the number of times Vova goes to sleep, the number of hours in a day and the segment of the good sleeping time.

The second line of the input contains $n$ integers $a_1, a_2, \dots, a_n$ ( $1 \le a_i < h$ ), where $a_i$ is the number of hours after which Vova goes to sleep the $i$ -th time.

输出格式

Print one integer — the maximum number of good sleeping times Vova can obtain if he acts optimally.

输入输出样例

输入 #1
7 24 21 23
16 17 14 20 20 11 22
输出 #1
3
C++ 编辑器
输入
输出