听说标算的点数是2^(n+1)级别的,也不知道我是不是比标算优一点? (话说这种题一眼看过去怎么跟题答一样) 然而并不是题答,没法手玩,来考虑一下一般解法: 考虑一个规模较小的问题:最后一位一定是0 不难发现变成了条件完全相同的一个子问题 再把最后一位加上 那么总共2^(n-1)个答案中的一部分会翻车, 若把会翻车的部分标记为1,不会翻车的标记为0,又得到一个完全相同的子问题(规模与上一个子问题一样) 那么原问题就可以表示为 (这一位的输入,两个子问题)进行一次操作 没了 考虑复杂度f(x)=2…

Backup Plan Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65535/65535 K (Java/Others)Total Submission(s): 93    Accepted Submission(s): 36Special Judge Problem Description Makomuno has N servers and M databases. All databases are synchroniz…

题目链接 题目描述 给你一个字符串a,每次询问一段区间的贡献 贡献定义: 每次从这个区间中随机拿出一个字符\(x\),然后把\(x\)从这个区间中删除,你要维护一个集合S 如果\(S\)为空,你\(rp\)减\(1\) 如果S中有一个元素不小于\(x\),则你\(rp\)减\(1\),清空\(S\) 之后将\(x\)插入\(S\) 由于你是大爷,平时做过的题考试都会考到,所以每次询问你搞完这段区间的字符之后最多还有多少\(rp\)?\(rp\)初始为\(0\) 询问之间不互相影响~ 输入输出格式…

对于这个神仙题,我还能说什么~ 第一个答案=$n/2$ 还是比较好猜的. 对于构造这个树,大概就是先从 $1$ 号节点向 $n/2$ 距离以内都连一条边,再在第 $n/2$ 个节点进行这个操作,然后从 $2$ 开始..... 你会发现不合法的情况就是有重边,然而这个是循环的,第 $n/2+1$ 次才会重,所以是可行的. #include <cstdio> #include <algorithm> #define setIO(s) freopen(s".in",&…

*这种题好像不用写题解... 题意: 一个人要改动别人的实验记录,实验记录记录是一个集合 实验记录本身满足:$max(X)-min(X)<=2$ 改动结果要求: 1.新的集合平均值和之前的一样 2.新的集合,$max(Y)<=max(X),min(Y)>=min(X)$ 求新一个和之前相同数值最少的新记录 题解: 首先考虑不同情况, 如果$max-min<=1$ :因为要保证平均值且值域受限制不变,无法改变值(增加一个值之后,要相应的把另外一值减小,而数值只有2/1种,改动没有意义…

Description   There are N<tex2html_verbatim_mark> marbles, which are labeled 1, 2,..., N<tex2html_verbatim_mark> . The N<tex2html_verbatim_mark> marbles are put in a circular track in an arbitrary order. In the top part of the track ther…

A permutation on the integers from 1 to n is, simply put, a particular rearrangement of these integers. Your task is to generate a given permutation from the initial arrangement 1, 2, 3, . . . , n using only two simple operations. •  Operation 1: You…

传送门 Description Vitya is studying in the third grade. During the last math lesson all the pupils wrote on arithmetic quiz. Vitya is a clever boy, so he managed to finish all the tasks pretty fast and Oksana Fillipovna gave him a new one, that is much…

ZCC loves cards Time Limit: 4000/2000 MS (Java/Others) Memory Limit: 65536/65536 K (Java/Others) Total Submission(s): 2362 Accepted Submission(s): 590 Problem Description ZCC loves playing cards. He has n magical cards and each has a number on it. He…

题目链接:https://codeforces.com/contest/1090/problem/D Vasya had an array of n integers, each element of the array was from 1 to n. He chose m pairs of different positions and wrote them down to a sheet of paper. Then Vasya compared the elements at these…