题目意思很简单,就是找n=p1+p2的种类数,具体看题目吧. 次重点是查找一定范围内的素数: 重点是用二分查找,不然会超时!!! #include<stdio.h> #include<string.h> int main() { ],num,s,l,r,mid; a[]=;s=; ;i<;i=i+)//这里是打出素数 { f=; ;j<s;j++) { if(a[j]*a[j]>i) break; ) { f=; break; } } ) a[s++]=i; }…

Problem Description Goldbach's Conjecture: For any even number n greater than or equal to 4, there exists at least one pair of prime numbers p1 and p2 such that n = p1 + p2. This conjecture has not been proved nor refused yet. No one is sure whether…

题意:给出n,问满足a+b=n且a,b都为素数的有多少对 将素数打表,再枚举 #include<iostream> #include<cstdio> #include<cstring> #include <cmath> #include<stack> #include<vector> #include<map> #include<algorithm> #define mod=1e9+7; using names…

Goldbach's Conjecture Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 5567    Accepted Submission(s): 2151 Problem Description Goldbach's Conjecture: For any even number n greater than or equal…

Vases and Flowers 题目链接 http://acm.hdu.edu.cn/showproblem.php?pid=4614 Problem Description Alice is so popular that she can receive many flowers everyday. She has N vases numbered from 0 to N-1. When she receive some flowers, she will try to put them…

http://lightoj.com/volume_showproblem.php?problem=1259 题目大意:给你一个数n,这个数能分成两个素数a.b,n = a + b且a<=b,问有几组这样的(a,b) 比较简单的哥德巴赫猜想题,不需要多说,但一般的素数判定会TLE,所以这里用的是素数筛选法 这里需要注意的是筛选出来素数数组的大小 #include<stdio.h> #include<math.h> #include<string.h> #inclu…

                                                                                1259 - Goldbach`s Conjecture 分拆素数和,本来很水的题,但硬生生跪了18+.这题卡内存实在太凶残了,MLT了10+,TLE了10+. 题意:在1e7内验证哥德巴赫猜想,求一个数拆分成两个不同的素数和有多少中方法. 思路:打表.就是打表. 但为什么会MLE呢,因为1e7的数组实在太大了,于是换了好几种写法优化,但…

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…

题意: 求正整数L和U之间有多少个整数x满足形如x=pk 这种形式,其中p为素数,k>1 分析: 首先筛出1e6内的素数,枚举每个素数求出1e12内所有满足条件的数,然后排序. 对于L和U,二分查找出小于U和L的最大数的下标,作差即可得到答案. #include <cstdio> #include <cmath> #include <algorithm> typedef long long LL; ; ; ]; ; LL a[maxn], cnt = ; void…

Can you find it? Time Limit: 10000/3000 MS (Java/Others)    Memory Limit: 32768/10000 K (Java/Others)Total Submission(s): 9180    Accepted Submission(s): 2401 Problem Description Give you three sequences of numbers A, B, C, then we give you a number…