链接: https://codeforces.com/contest/1230/problem/B 题意: Ania has a large integer S. Its decimal representation has length n and doesn't contain any leading zeroes. Ania is allowed to change at most k digits of S. She wants to do it in such a way that S…

Codeforces Round #588 (Div. 2)-E. Kamil and Making a Stream-求树上同一直径上两两节点之间gcd的和 [Problem Description] 给你一棵树,树上每个节点都有一个权值.定义\(1\sim v\)的最短路径所经过的所有节点\(u\)称为\(v\)节点的祖先.定义函数\(f(u,v)=gcd(u,t1,t2,\dots,v)\),其中\(u,t1,t2,\dots\)都是\(v\)的祖先.求\(\sum f(u,v)\). […

题目链接:Codeforces Round #275 (Div. 2) C - Diverse Permutation 题意:一串排列1~n.求一个序列当中相邻两项差的绝对值的个数(指绝对值不同的个数)为k个.求序列. 思路:1~k+1.构造序列前段,之后直接输出剩下的数.前面的构造能够依据,两项差的绝对值为1~k构造. AC代码: #include <stdio.h> #include <string.h> int ans[200010]; bool vis[100010]; i…

传送门 A. Dawid and Bags of Candies 乱搞. Code #include <bits/stdc++.h> #define MP make_pair #define fi first #define se second #define sz(x) (int)(x).size() //#define Local using namespace std; typedef long long ll; typedef pair<int, int> pii; con…

链接: https://codeforces.com/contest/1230/problem/E 题意: Kamil likes streaming the competitive programming videos. His MeTube channel has recently reached 100 million subscribers. In order to celebrate this, he posted a video with an interesting problem…

链接: https://codeforces.com/contest/1230/problem/D 题意: Marcin is a coach in his university. There are n students who want to attend a training camp. Marcin is a smart coach, so he wants to send only the students that can work calmly with each other. L…

链接: https://codeforces.com/contest/1230/problem/C 题意: Anadi has a set of dominoes. Every domino has two parts, and each part contains some dots. For every a and b such that 1≤a≤b≤6, there is exactly one domino with a dots on one half and b dots on th…

链接: https://codeforces.com/contest/1230/problem/A 题意: Dawid has four bags of candies. The i-th of them contains ai candies. Also, Dawid has two friends. He wants to give each bag to one of his two friends. Is it possible to distribute the bags in suc…

Contest Page 因为一些特殊的原因所以更得不是很及时-- A sol 不难发现当某个人diss其他所有人的时候就一定要被删掉. 维护一下每个人会diss多少个人,当diss的人数等于剩余人数$-1$的时候放队列里,每一次取队头更新其他人diss的人数. code B sol 一个结论:对于序列$a_1,a_2,...,a_n$,其前缀$gcd$数量不超过$log_2a_i$种.证明考虑从前往后计算前缀$gcd$,那么从第$i-1$个$gcd$到第$i$个$gcd$,数值要么不变要么至少…

1. 1229A Marcin and Training Camp 大意: 给定$n$个对$(a_i,b_i)$, 要求选出一个集合, 使得不存在一个元素好于集合中其他所有元素. 若$a_i$的二进制中某一位为$1$, $a_j$对应位为$0$, 那么$(a_i,b_i)$好于$(a_j,b_j)$. 显然出现次数不少于$2$的数都可以选, 然后再把包含关系的数全选了即可. #include <iostream> #include <sstream> #include <al…