Gravatar
喵妹子
积分:3
提交:3 / 4

别打我,我是炫彩猫妹子!

Gravatar
0
积分:2001
提交:530 / 1238
最后一句话亮了...话说让他切题的那个人坐我左边*4

Gravatar
/k
积分:1684
提交:345 / 543
不就是偷懒少打几个特判吗,被Hack得好惨

Gravatar
Satoshi
积分:2996
提交:678 / 1922
你们竟然还Hack.......%%%%%%%%%

Gravatar
stdafx.h
积分:3332
提交:889 / 1556
hhd

Gravatar
神利·代目
积分:3115
提交:802 / 1626
已加,但我并不是作者

Gravatar
神利·代目
积分:3115
提交:802 / 1626
回复 @zys :
ORZ

Gravatar
神利·代目
积分:3115
提交:802 / 1626
回复 @Satoshi :
有两种做法:
一种是2008rank1做法的改进版
另一种是我的做法,在状态之间连转移边,构建拓扑图
都是n^3的,不过不知道为什么我的这么慢。。。。。。

Gravatar
Satoshi
积分:2996
提交:678 / 1922
回复 @stone :
所以Rank1的做法是什么......

Gravatar
stone
积分:1531
提交:406 / 764
回复 @Satoshi :
M是任意两点之间边数。

Gravatar
stone
积分:1531
提交:406 / 764
回复 @Satoshi :
但是那些写DP的估计写挂了的过不了。所以时限放宽到1s。加这题是为了宣传Rank1的做法。

Gravatar
Satoshi
积分:2996
提交:678 / 1922
回复 @stone :
M是什么,你们写的是DP吗?

Gravatar
stone
积分:1531
提交:406 / 764
回复 @Satoshi :
O(NM),本来时限是0.5s的

Gravatar
Satoshi
积分:2996
提交:678 / 1922
回复 @溪哥 :
你们是怎么写的?貌似看着是O(n^2)

Gravatar
zys
积分:1679
提交:471 / 964
回复 @Satoshi :

Gravatar
Satoshi
积分:2996
提交:678 / 1922
作者请加数据范围

Gravatar
神利·代目
积分:3115
提交:802 / 1626
同样是n^3的做法,为什么差别这么大?

Gravatar
Satoshi
积分:2996
提交:678 / 1922
证明:
Sort the haybales by location. Consider two haybales i and j such that Bessie can start somewhere between those haybales and break through all the haybales from i+1 to j−1, but she can't break haybale i or haybale j.
It must be the case then that no haybale between i and j is strictly taller than those two.
That motivates the following O(NlogN)solution:
Sort the haybales in decreasing order of size. Consider having an empty road, and place the haybales in that order. When placing a haybale, look immediately to its left and to its right and see if you can break through either one of those haybales if you were inside that interval. Mark that interval as "trapped" if so.
This will be O(NlogN)
as long as you check to make sure that the interval isn't already marked as trapped.
按重量从大到小排序,可以保证区间不会被漏掉

Gravatar
mikumikumi
积分:4118
提交:830 / 1893
莫比乌斯反演的裸题。。

Gravatar
asddddd
积分:614
提交:109 / 351
我竟然把sv设成0了。。。都可以去卖萌了QAQ