链接:http://codeforces.com/contest/437/problem/A A. The Child and Homework time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Once upon a time a child got a test consisting of multiple-choice qu…

题目链接:http://codeforces.com/problemset/problem/438/D 给你n个数,m个操作,1操作是查询l到r之间的和,2操作是将l到r之间大于等于x的数xor于x,3操作是将下标为k的数变为x. 注意成段更新的时候,遇到一个区间的最大值还小于x的话就停止更新. #include <iostream> #include <cstdio> #include <cstring> using namespace std; typedef __…

D. The Child and Sequence Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/438/problem/D Description At the children's day, the child came to Picks's house, and messed his house up. Picks was angry at him. A lot of important…

B. The Child and Zoo Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/438/problem/B Description Of course our child likes walking in a zoo. The zoo has n areas, that are numbered from 1 to n. The i-th area contains ai animal…

A. The Child and Toy Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/438/problem/A Description On Children's Day, the child got a toy from Delayyy as a present. However, the child is so naughty that he can't wait to destroy…

注意题目长度不能考虑前缀,而且如果即存在一个选项的长度的两倍小于其他所有选项的长度,也存在一个选项的长度大于其他选项长度的两倍,则答案不是一个好的选择,只能选择C. #include <iostream> #include <vector> #include <string> #include <algorithm> using namespace std; struct Answer{ char item; int length; Answer():ite…

注意此题,每一个部分都有一个能量值v[i],他移除第i部分所需的能量是v[f[1]]+v[f[2]]+...+v[f[k]],其中f[1],f[2],...,f[k]是与i直接相连(且还未被移除)的部分的编号. 注意题目移除的都是与第i部分直接相连的部分的能量值, 将本题目简化得,只考虑两个点1和2,1和2相连,1的能量值是10,2的能量值是20, 移除绳子时,要保持能量最小,可以移除部分2,这样移除的能量就是与2相连的部分1的能量即是10: 故每次相连两部分都移除能量值大的即可 #includ…

感觉不会再爱了,呜呜! A题原来HACK这么多!很多人跟我一样掉坑了! If there is some choice whose description at least twice shorter than all other descriptions, or at least twice longer than all other descriptions, then the child thinks the choice is great. If there is exactly one…

题目链接 题意: 给定goal和limit,求1-limit中的若干个数,每一个数最多出现一次,且这些数的lowbit()值之和等于goal,假设存在这种一些数,输出个数和每一个数:否则-1 分析: 先考虑一下比較普通的情况,给一些数,和一个goal,问时候能达到.(最好还是设这些数已经从大到小排序) 考虑能否够贪心,对于当前的数x: 1.之后的数的和能等于x,那么假设x<=goal,显然必须选x: 2.之后的数的和能等于x-1,那么同上(这个情况就是二进制的情况) 3.之后的数的和不包含上述两…

     好题啊,被HACK了.曾经做题都是人数越来越多.这次比赛 PASS人数 从2000直掉 1000人  被HACK  1000多人! ! ! ! 没见过的科技啊 1 2 4 8 这组数 被黑的 A. The Child and Homework time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Once upon a ti…

题意:有一个集合,求有多少形态不同的二叉树满足每个点的权值都属于这个集合并且总点权等于i 题解:先用生成函数搞出来\(f(x)=f(x)^2*c(x)+1\) 然后转化一下变成\(f(x)=\frac{2}{1+\sqrt{1-4*c(x)}}\) 然后多项式开根和多项式求逆即可(先对下面的项开根,然后再求逆) 多项式开根: \(B(x)^2=A(x) \bmod x^{ \lfloor \frac{n}{2} \rfloor}\) \(B'(x)^2=A(x) \bmod x^{ \lfloo…

D. The Child and Sequence time limit per test 4 seconds memory limit per test 256 megabytes input standard input output standard output At the children's day, the child came to Picks's house, and messed his house up. Picks was angry at him. A lot of…

D. The Child and Sequence time limit per test 4 seconds memory limit per test 256 megabytes input standard input output standard output At the children's day, the child came to Picks's house, and messed his house up. Picks was angry at him. A lot of…

给你一张无向图,每个点有一个权值,对于一条从l到r 的边权值是l到r路径上最小的点的权值,(多条路取最大的权值),然后求每两个点之间的权值和/点对数 题解:并查集维护,先从点大的边排序,然后依次加边,这样每次加进来的保证是当前最大 的,然后每次合并都要加上两端的最小值*两端的size,类似与每一个最小值算贡献 #pragma comment(linker, "/stack:200000000") #pragma GCC optimize("Ofast,no-stack-pro…

D. The Child and Zoo time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Of course our child likes walking in a zoo. The zoo has n areas, that are numbered from 1 to n. The i-th area contains …

A. The Child and Homework time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Once upon a time a child got a test consisting of multiple-choice questions as homework. A multiple-choice question…

这几次CF都挺惨.. A 没条边权设为两端点的最小点权,最后加起来. 数组开小,WA一次 #include <iostream> #include<cstdio> #include<cstring> #include<algorithm> #include<stdlib.h> #include<vector> #include<cmath> #include<queue> #include<set>…

B. The Child and Set   At the children's day, the child came to Picks's house, and messed his house up. Picks was angry at him. A lot of important things were lost, in particular the favorite set of Picks. Fortunately, Picks remembers something about…

D. The Child and Sequence   At the children's day, the child came to Picks's house, and messed his house up. Picks was angry at him. A lot of important things were lost, in particular the favorite sequence of Picks. Fortunately, Picks remembers how t…

题目例如以下: C. The Child and Toy time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output On Children's Day, the child got a toy from Delayyy as a present. However, the child is so naughty that he can't…

<传送门> [题目大意] 给你一个sum和一个limit,现在要你在1~limit中找到一些数来使得这些数的和等于sum,如果能找到的话就输出找到的数的个数和这些数,未找到输出"-1". 比赛的时候被hack了. [题目分析] 这题需要将所有的数的lowbit先求出来,然后按照大小排序,然后从后往前判断,如果这个数小于sum那么这个数就是可以构成sum的数,选进去,完了以后判断sum的值是否为0就可以了.做题的时候没将题目理解透彻. #include<bits/std…

Problem  Codeforces Round #556 (Div. 2) - D. Three Religions Time Limit: 3000 mSec Problem Description Input Output Sample Input 6 8abdabc+ 1 a+ 1 d+ 2 b+ 2 c+ 3 a+ 3 b+ 1 c- 2 Sample Output YESYESYESYESYESYESNOYES 题解:动态规划,意识到这个题是动态规划之后难点在于要优化什么东西,本题…

Codeforces Round #366 (Div. 2) A I hate that I love that I hate it水题 #I hate that I love that I hate it n = int(raw_input()) s = "" a = ["I hate that ","I love that ", "I hate it","I love it"] for i in ran…

Codeforces Round #354 (Div. 2) Problems     # Name     A Nicholas and Permutation standard input/output 1 s, 256 MB    x3384 B Pyramid of Glasses standard input/output 1 s, 256 MB    x1462 C Vasya and String standard input/output 1 s, 256 MB    x1393…

直达–>Codeforces Round #368 (Div. 2) A Brain’s Photos 给你一个NxM的矩阵,一个字母代表一种颜色,如果有”C”,”M”,”Y”三种中任意一种就输出”#Color”,如果只有”G”,”B”,”W”就输出”#Black&White”. #include <cstdio> #include <cstring> using namespace std; const int maxn = 200; const int INF =…

 cf之路,1,Codeforces Round #345 (Div. 2) ps:昨天第一次参加cf比赛,比赛之前为了熟悉下cf比赛题目的难度.所以做了round#345连试试水的深浅.....       其实这个应该是昨天就写完的,不过没时间了,就留到了今天.. 地址:http://codeforces.com/contest/651/problem/A A. Joysticks time limit per test 1 second memory limit per test 256…

Codeforces Round #279 (Div. 2) 做得我都变绿了! Problems     # Name     A Team Olympiad standard input/output 1 s, 256 MB  x2377 B Queue standard input/output 2 s, 256 MB  x1250 C Hacking Cypher standard input/output 1 s, 256 MB  x740 D Chocolate standard in…

Codeforces Round #262 (Div. 2) 1003 C. Present time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Little beaver is a beginner programmer, so informatics is his favorite subject. Soon his info…

Codeforces Round #262 (Div. 2) 1004 D. Little Victor and Set time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Little Victor adores the sets theory. Let us remind you that a set is a group of…

A: 题目大意: 在一个multiset中要求支持3种操作: 1.增加一个数 2.删去一个数 3.给出一个01序列,问multiset中有多少这样的数,把它的十进制表示中的奇数改成1,偶数改成0后和给出的01序列相等(比较时如果长度不等各自用0补齐) 题解: 1.我的做法是用Trie数来存储,先将所有数用0补齐成长度为18位,然后就是Trie的操作了. 2.官方题解中更好的做法是,直接将每个数的十进制表示中的奇数改成1,偶数改成0,比如12345,然后把它看成二进制数10101,还原成十进制是2…