题目连接 http://acm.hdu.edu.cn/showproblem.php?pid=4715 Difference Between Primes Description All you know Goldbach conjecture.That is to say, Every even integer greater than 2 can be expressed as the sum of two primes. Today, skywind present a new conje…

http://acm.hdu.edu.cn/showproblem.php?pid=4715 [code]: #include <iostream> #include <cstdio> #include <cstring> #include <cmath> using namespace std; #define N 1000151 ]; ]; ]; ]; ; int lowbit(int i) { return i&-i; } void add(i…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=4715 思路:先打个素数表,然后判断一下就可以了. #include<iostream> #include<cstdio> #include<cstring> #include<algorithm> #include<cmath> using namespace std; ]; ]; int main() { ; memset(isprime,true…

Difference Between Primes Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 3339    Accepted Submission(s): 953 Problem Description All you know Goldbach conjecture.That is to say, Every even int…

Difference Between Primes Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 860 Accepted Submission(s): 278 Problem Description All you know Goldbach conjecture.That is to say, Every even integer gr…

题意:给出一个偶数(不论正负),求出两个素数a,b,能够满足 a-b=x,素数在1e6以内. 只要用筛选法打出素数表,枚举查询下就行了. 我用set储存素数,然后遍历set里面的元素,查询+x后是否还是素数. 注意,偶数有可能是负数,其实负数就是将它正数时的结果颠倒就行了. 代码: /* * Author: illuz <iilluzen[at]gmail.com> * Blog: http://blog.csdn.net/hcbbt * File: 10.cpp * Create Date:…

Difference Between Primes Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 528    Accepted Submission(s): 150 Problem Description All you know Goldbach conjecture.That is to say, Every even inte…

#include<stdio.h> #include<string.h> int prime[1100000],p[1000000],ans; void pri() {     int i,j,k;     memset(prime,-1,sizeof(prime));  prime[0]=prime[1]=0;     for(i=2;i<=1000;i++)         if(prime[i]==-1) {             for(j=i*2;j<=10…

这道题很坑,注意在G++下提交,否则会WA,还有就是a或b中较大的那个数的范围.. #include<iostream> #include<cstdio> #include<cstring> using namespace std; const int maxn = 1e6 + 10; int prime[maxn]; bool isprime[maxn]; int init() { memset(prime, 0, sizeof(prime)); isprime[0]…

http://acm.hdu.edu.cn/showproblem.php?pid=4715 Difference Between Primes Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Problem Description All you know Goldbach conjecture.That is to say, Every even integer great…