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====== 2020 Summer Week 5 Report ======
====== 团队训练 ======
[[2020-2021:teams:mian:nowcoder_training:2020_multi-university_training_contest_9|2020牛客暑期多校训练营（第九场）]] ''%%task:7/8/12%%'', ''%%rank:32/1041%%''
[[2020-2021:teams:mian:nowcoder_training:2020_multi-university_training_contest_10|2020牛客暑期多校训练营（第十场）]] ''%%task:3/3/10%%'', ''%%rank:140/986%%''
[[2020-2021:teams:mian:hdu_training:2019_multi-university_training_contest_1|2019 Multi-University Training Contest 1]]
====== 本周推荐 ======
===== Pantw =====
[[https://atcoder.jp/contests/agc047/tasks/agc047_c|AGC047C]]
* 分类：数论，卷积
* 题意：给一堆数，求两两乘积模某质数 p 的和。
* 做法：把数用原根的幂表示，然后当多项式卷起来。
* 评论：比较经典的转化。
===== Withinlover =====
[[https://codeforces.com/problemset/problem/1372/E|CF1372 E]]
* 分类：区间DP
* 题意：给定一个n*m的网格，每一行都分为若干组，每组中可以选一个位置填1，求每列1的数量的平方的最大值。
* 做法：区间DP，$dp[l][r]$ 表示仅使用完全包含于 $[l, r]$ 的组可以达到的最大值。暴力转移。
* 评论：dp很容易想到，但是这个仅使用完全包含于 $[l, r]$ 的组这一限制不好想。
===== Gary =====
[[http://acm.hdu.edu.cn/showproblem.php?pid=6583|HDU6583]]
* 分类：SAM，DP
* 题意：给定字符串 每次可以添加一个字符花费P 也可以复制前面一段花费Q 求最小构成该串的代价
* 解法：考虑dp过程 f(i)＝Min{f(i-1)+P,f(i-j)+Q(j满足i-j到i这一段串在之前出现过)} 考虑如何求出最大的j 可以对原串构建SAM 记录每个节点匹配的位置 如果这个位置不能满足就跳到parent节点继续匹配 全部跳的过程复杂度是O(串长)
* 评论：sam上的操作不太熟悉 写了半天才调出来 hdu上还爆栈了
====== 个人训练 ======
===== Pantw =====
==== 专题 ====
__builtin
==== 比赛 ====
[[https://atcoder.jp/contests/agc047|AGC047]]
==== 题目 ====
SRM305A, AGC047A, AGC047B, AGC047C, AGC047E1
===== Withinlover =====
==== 专题 ====
无
==== 比赛 ====
无
==== 题目 ====
[[https://codeforces.com/problemset/problem/1372/E|CF1372 E]]
===== Gary =====
==== 专题 ====
==== 比赛 ====
[[https://codeforces.com/contest/1391|Codeforces Round #663 (Div. 2)]]
[[https://atcoder.jp/contests/agc047|AtCoder Grand Contest 047]]
==== 题目 ====
AtCoder Grand Contest 047 A,B,C
Codeforces Round #663 (Div. 2) A,B,C,D,E
Codeforces Round #662 (Div. 2) C,D,E1,E2