Codeforces Round #460 (Div. 2)

A

签到



B

题意

定义:一个数(没有前缀0)的各个位数之和为10位“perfec”数,问第k个“perfect”数位多少(1<=k<=1e5)

分析

一开始找错了,以为会超过1e9,通过理性的分析不难发现,最大不超过1e9,强行打个表即可



C

签到



D

题意

n个点m条边的有向图,每个点有一个数字(可以重复,0~25),定义一条路径的权值为该路径出现数字最多的数字的次数,若有环输出-1,否则输出最大值

分析

思路:首先直接dfs肯定不行,最坏情况n^2

正解:拓扑排序+dp

拓扑排序的时候dp即可

定义:dp[i][j]:第i个点数字j的最大值

转移 :直接从上一个节点到当前节点转移即可

原文地址:https://www.cnblogs.com/Superwalker/p/8407712.html

时间: 2024-11-06 03:42:58

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