codeforces 547E Mike and Friends 题意 题解 代码 #include<bits/stdc++.h> using namespace std; #define fi first #define se second #define mp make_pair #define pb push_back #define rep(i, a, b) for(int i=(a); i<(b); i++) #define per(i, a, b) for(int i=(b)…

题意: 给出\(n\)个字符串\(s_i\)和\(q\)个询问: \(l,r,k\):\(\sum\limits_{i=l}^{r}count(i, k)\),其中\(count(i,j)\)表示\(s_j\)作为子串在\(s_i\)中出现的次数 分析: 先不考虑查询中\(l,r\)的限制,考虑该字符串\(s_k\)在一个字符串集合中出现的次数. 先将这个字符串集合插入到一棵Trie数中,并且每经过一个节点就将其对应的\(val\)值加\(1\). 这样\(s_k\)对应节点的\(val\)值就…

题面传送门 好久每做过 AC 自动机的题了--做几个题回忆一下罢 AC 自动机能够解决多串匹配问题,注意是匹配,碰到前后缀的问题那多半不在 AC 自动机能解决的范围内. 在初学 AC 自动机的时候相信大家都做过一道题叫做 P2414 [NOI2011] 阿狸的打字机.在这道题中我们用到了两棵树,一棵就是所有串的字典树,称为 trie 树,令一棵是求出每个点的 \(fail_i\) 后,对于所有不是根节点的 \(i\) 连边 \((fail_i,i)\) 后形成的树,称为 fail 树. 在那道题…

hdu4135 求[L,R]范围内与N互质的数的个数. 分别求[1,L]和[1,R]和n互质的个数,求差. 利用容斥原理求解. 二进制枚举每一种质数的组合,奇加偶减. #include <bits/stdc++.h> using namespace std; typedef long long ll; ; int fac[N], cnt; void factor(int n) { cnt = ; int limit = sqrt(n); ; i <= limit; ++i) { ) fa…

codeforces 689 Mike and Shortcuts(最短路) 原题 任意两点的距离是序号差,那么相邻点之间建边即可,同时加上题目提供的边 跑一遍dijkstra可得1点到每个点的最短路,时间复杂度是O(mlogm) #include <cstdio> #include <iostream> #include <cstring> #include <queue> #include <vector> using namespace s…

What-The-Fatherland is a strange country! All phone numbers there are strings consisting of lowercase English letters. What is double strange that a phone number can be associated with several bears! In that country there is a rock band called CF con…

传送门 B. Mike and Fun time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Mike and some bears are playing a game just for fun. Mike is the judge. All bears except Mike are standing in an n × m g…

Mike has always been thinking about the harshness of social inequality. He's so obsessed with it that sometimes it even affects him while solving problems. At the moment, Mike has two sequences of positive integers A = [a1, a2, ..., an] and B = [b1, …

C. Mike and gcd problem time limit per test: 2 seconds memory limit per test: 256 megabytes input: standard input output: standard output Mike has a sequence A = [a1, a2, ..., an] of length n. He considers the sequence B = [b1, b2, ..., bn] beautiful…

A. Mike and palindrome time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Mike has a string s consisting of only lowercase English letters. He wants to change exactly one character from the s…