考场 T1 貌似是 luogu 上原题 T2 计数,想起了这题和这题,但没有 \(n^2\) 一档的分...准备打个表 T3 期望 DP,但暴力是 \(O(qn)\) 的,发现 \(combo\) 的形式像一次函数,应该要用 DS 维护. 7.30 开写,8.00 拍上 T1 T2 打表发现填的数是每个数最后一次出现位置的升序那就有 53pts,比较满意.然后一直在想怎么改上面那题的方程,弃的比较早 T3 一度推出的暴力 DP 的式子,写出来不对,调了调也没啥思路,只能拼部分分了.sub6 只要…

Sum of Consecutive Prime Numbers Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 20050   Accepted: 10989 Description Some positive integers can be represented by a sum of one or more consecutive prime numbers. How many such representatio…

Farey Sequence 题意:给定一个数n,求在[1,n]这个范围内两两互质的数的个数.(转化为给定一个数n,比n小且与n互质的数的个数) 知识点: 欧拉函数: 普通求法: int Euler(int n) { int ans=n; for(int i=0;i<cnt&&prime[i]<=n;i++) { if(n%prime[i]==0) { ans=ans-ans/prime[i]; while(n%prime[i]==0) n/=prime[i]; } } if(…

题目链接: 传送门 Sum of Consecutive Prime Numbers Time Limit: 1000MS     Memory Limit: 65536K Description Some positive integers can be represented by a sum of one or more consecutive prime numbers. How many such representations does a given positive intege…

题目链接: 传送门 Prime Land Time Limit: 1000MS     Memory Limit: 10000K Description Everybody in the Prime Land is using a prime base number system. In this system, each positive integer x is represented as follows: Let {pi}i=0,1,2,... denote the increasing…

POJ 2739 Sum of Consecutive Prime Numbers Time Limit:1000MS     Memory Limit:65536KB     64bit IO Format:%lld & %llu   Description Some positive integers can be represented by a sum of one or more consecutive prime numbers. How many such representati…

Prime Query Time Limit: 1 Second Memory Limit: 196608 KB You are given a simple task. Given a sequence A[i] with N numbers. You have to perform Q operations on the given sequence. Here are the operations: A v l, add the value v to element with index…

Prime Query Time Limit: 1 Second      Memory Limit: 196608 KB You are given a simple task. Given a sequence A[i] with N numbers. You have to perform Q operations on the given sequence. Here are the operations: A v l, add the value v to element with i…

Number Sequence Time Limit: 10000/3000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others) Problem Description Given a number sequence b1,b2…bn. Please count how many number sequences a1,a2,...,an satisfy the condition that a1*a2*...*an=b1*…

在刚刚写完代码的时候才发现我以前交过这道题,可是没有过. 后来因为不理解代码,于是也就不了了之了. 可说呢,那时的我哪知道什么DFS深搜的东西啊,而且对递归的理解也很肤浅. 这道题应该算HDU 2610 Sequence one的简化版,判重也非常简单. 其他也没有什么好说的了,直接上代码吧. //#define LOCAL #include <iostream> #include <cstdio> #include <cstring> #include <cma…