POJ 2262 Goldbach's Conjecture(素数相关) http://poj.org/problem?id=2262 题意: 给你一个[6,1000000]范围内的偶数,要你将它表示成两个素数相加和的形式.假设存在多组解,请输出两个素数差值最大的解. 分析: 首先我们用素数筛选法求出100W以内的全部素数. 筛选法求素数可见: http://blog.csdn.net/u013480600/article/details/41120083 对于给定的数X,假设存在素数a+素数b…

http://poj.org/problem?id=2262 Goldbach's Conjecture Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 34323   Accepted: 13169 Description In 1742, Christian Goldbach, a German amateur mathematician, sent a letter to Leonhard Euler in whic…

题目:http://poj.org/problem?id=2262 大水题的筛质数. #include<iostream> #include<cstdio> #include<cstring> using namespace std; const int N=1e6; ],cnt; ]; void init() { ;i<=N;i++) { if(!vis[i])pri[++cnt]=i; ;j<=cnt&&(long long)i*pri[…

题目链接: https://cn.vjudge.net/problem/POJ-2262 题目描述: In 1742, Christian Goldbach, a German amateur mathematician, sent a letter to Leonhard Euler in which he made the following conjecture: Every even number greater than 4 can be written as the sum of t…

http://poj.org/problem?id=2262 题意: 哥德巴赫猜想,把一个数用两个奇素数表示出来. 思路:先用Eratosthenes筛法打个素数表,之后枚举即可. #include<iostream> #include<algorithm> #include<string> #include<cstring> #include<cmath> using namespace std; ; int n; int vis[maxn];…

题目链接:http://poj.org/problem?id=2262 哥德巴赫猜想肯定是正确的 思路: 筛出n范围内的所有奇质数,对每组数据试过一遍即可, 为满足b-a取最大,a取最小 时空复杂度分析: 在1e6内约有8e4个奇质数,因为a <= b,时间复杂度在T*4e4+1e6等级.一般T为1e3,足以承受 空间复杂度为1e6,足以承受 #include <cstdio> #include <cstring> #include <algorithm> usi…

素数判定...很简单= =.....只是因为训练题有,所以顺便更~ #include<cstdio> #include<memory.h> #define maxn 5000005 int prime[maxn]; void f() { memset(prime,,sizeof(prime)); prime[] = prime[] = ; ; i < maxn; i++) { if(!prime[i]) { * i; j < maxn; j += i) prime[j]…

质数(prime number)又称素数,有无限个.一个大于1的自然数,除了1和它本身外,不能被其他自然数整除,换句话说就是该数除了1和它本身以外不再有其他的因数:否则称为合数.      最小的质数是2. [例1]Goldbach's Conjecture (POJ 2262) Description In 1742, Christian Goldbach, a German amateur mathematician, sent a letter to Leonhard Euler in w…

It was proposed by Christian Goldbach that every odd composite number can be written as the sum of a prime and twice a square. 9 = 7 + 21215 = 7 + 22221 = 3 + 23225 = 7 + 23227 = 19 + 22233 = 31 + 212 It turns out that the conjecture was false. What…

这是 meelo 原创的 IEEEXtreme极限编程大赛题解 Xtreme 10.0 - Goldbach's Second Conjecture 题目来源 第10届IEEE极限编程大赛 https://www.hackerrank.com/contests/ieeextreme-challenges/challenges/goldbachs-second-conjecture An integer p > 1 is called a prime if its only divisors ar…