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2020-2021:teams:farmer_john:2020暑假精选题目:网络流 [CVBB ACM Team]

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2020-2021:teams:farmer_john:2020暑假精选题目:网络流

网络流

CF808F

题意

$n$张卡,每张卡有数值$a$,价值$b$,等级$c$三个值,你可以更改自己的等级,你需要选一些卡,满足这些卡两两之间的数值和都不是质数,所有卡的等级不超过你的等级,且所有卡的价值之和不小于$k$,问你最少需要多少等级。$(n \le 100, a \le 10^5)$

题解

枚举等级,进行如下的验证:除了$2$所有质数都是奇数,因此如果两张卡不能在一起就将他们相连构成的图是二分图,用总价值减去最小割即可。另外,两张$1$可以组成$2$,因此要对$1$进行特判,保证只能选一个$1$。

2020-2021/teams/farmer_john/2020暑假精选题目/网络流.txt · 最后更改: 2020/09/04 10:17 由 jjleo