QOJ.ac

QOJ

Time Limit: 2 s Memory Limit: 256 MB Total points: 100

#21053. 才艺表演

Statistics

Farmer John 带着编号为 $1\ldots N$ 的 $N$ 头奶牛参加县集市的年度奶牛才艺表演!奶牛 $i$ 的体重 $w_i$ 和才艺值 $t_i$ 都是整数。

今年的新规则让他很惊讶:

(i) 必须派出总重量至少为 $W$ 的奶牛队伍,以保证参赛的是强大的队伍,而不只是强大的个体。

(ii) 总才艺与总重量比值最大的队伍获胜。

所有奶牛总重量至少为 $W$,所以能组成符合 (i) 的队伍。请确定这样的队伍能达到的最大才艺重量比。

输入格式

第 1 行包含 $N$($1 \leq N \leq 250$)和 $W$($1 \leq W \leq 1000$)。接下来 $N$ 行各用两个整数描述一头奶牛:$w_i$($1 \leq w_i \leq 10^6$)和 $t_i$($1 \leq t_i \leq 10^3$)。

输出格式

确定总重量至少为 $W$ 的队伍的最大总才艺与总重量比。如果答案为 $A$,输出 $1000A$ 向下取整的值,以保持整数输出;向下取整会去掉小数部分,非整数向下舍入为整数。

样例

输入格式 1

3 15
20 21
10 11
30 31

输出格式 1

1066

说明

本例中,只选才艺 11、重量 10 的奶牛能得到最高比值,但重量至少要 15,所以还要选才艺 21、重量 20 的奶牛。比值为 $(11+21)/(10+20)=32/30=1.0666666...$,乘 1000 后向下取整得到 1066。

题目作者:Brian Dean

Discussions

About Discussions

The discussion section is only for posting: General Discussions (problem-solving strategies, alternative approaches), and Off-topic conversations.

This is NOT for reporting issues! If you want to report bugs or errors, please use the Issues section below.

Open Discussions 0
No discussions in this category.

Issues

About Issues

If you find any issues with the problem (statement, scoring, time/memory limits, test cases, etc.), you may submit an issue here. A problem moderator will review your issue.

Guidelines:

  1. This is not a place to publish discussions, editorials, or requests to debug your code. Issues are only visible to you and problem moderators.
  2. Do not submit duplicated issues.
  3. Issues must be filed in English or Chinese only.
Active Issues 0
No issues in this category.
Closed/Resolved Issues 0
No issues in this category.