A - Noldbach problem 题面链接 http://codeforces.com/contest/17/problem/A 题面 Nick is interested in prime numbers. Once he read about Goldbach problem. It states that every even integer greater than 2 can be expressed as the sum of two primes. That got Nic…

Description Noldbach problem time limit per test: 2 seconds memory limit per test: 64 megabytes input: standard input output: standard output Nick is interested in prime numbers. Once he read about Goldbach problem. It states that every even integer…

题意: 判断从[2,N]中是否有超过[包括]K个数满足:等于一加两个相邻的素数. 思路: 枚举. 也可以:筛完素数,枚举素数,直到相邻素数和超过N.统计个数 代码: int n,k; int prime[1005]; int cn=0; bool isPrime(int x){ if(x==2) ret true; for(int i=2;i*i<=x;++i) if(x%i==0) ret false; ret true; } void sieve(){ rep(i,2,n){ if(isPr…

Content 若一个素数可以用比它小的相邻的两个素数的和加 \(1\) 表示,那么称这个素数为"好素数". 给定两个正整数 \(n,k\),问从 \(2\) 到 \(n\) 的好素数个数是否 \(\geqslant k\). 数据范围:\(2\leqslant n\leqslant 1000,0\leqslant k\leqslant 1000\). Solution 直接通过埃氏筛得到 \(1000\) 以内的素数,再通过直接暴力枚举预处理出 \(1000\) 以内的"好…

A. Noldbach problem Nick is interested in prime numbers. Once he read about Goldbach problem. It states that every even integer greater than 2 can be expressed as the sum of two primes. That got Nick's attention and he decided to invent a problem of…

求有限集传递闭包的 Floyd Warshall 算法(矩阵实现) 其实就三重循环.zzuoj 1199 题 链接 http://acm.zzu.edu.cn:8000/problem.php?id=1199 Problem B: 大小关系 Time Limit: 2 Sec  Memory Limit: 128 MBSubmit: 148  Solved: 31[Submit][Status][Web Board] Description 当我们知道一组大小关系之后,可判断所有关系是否都能成立…

Gson解析JSON字符串时出现了下面的错误: No-args constructor for class X does not exist. Register an InstanceCreator with Gson for this type to fix this problem. 解决的办法是把对应的Class改成静态类.…

C - NP-Hard Problem Crawling in process... Crawling failed Time Limit:2000MS     Memory Limit:262144KB     64bit IO Format:%I64d & %I64u Submit Status Practice CodeForces 688C uDebug Description   Input   Output   Sample Input   Sample Output   Hint…

I joined the NodeJS online Course three weeks ago, but now I'm late about 2 weeks. I pay the codeschool yearly subscribed, but I have lost the track long time. I get more weight than expected. I like more and more my MacBook Pro I maybe go to the UST…

    Programming Contest Problem Types Hal Burch conducted an analysis over spring break of 1999 and made an amazing discovery: there are only 16 types of programming contest problems! Furthermore, the top several comprise almost 80% of the problems s…