hdu4715之素数筛选 - c++编程基础

Difference Between Primes

Time Limit: 2000/1000 MS ( Java/Others) Memory Limit: 32768/32768 K (Java/Others)

Total Submission(s): 673 Accepted Submission(s): 216

Problem 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 conjecture: every even integer can be expressed as the difference of two primes. To validate this conjecture, you are asked to write a program.

Input

The first line of input is a number nidentified the count of test cases(n<10^5). There is a even number xat the next nlines. The absolute value of xis not greater than 10^6.

Output

For each number xtested, outputstwo primes aand bat one line separatedwith one space where a-b=x. If more than one group can meet it, output the minimum group. If no primes can satisfy it, output 'FAIL'.

Sample Input

Sample Output

11 5

13 3

23 3

Source

2013 ACM/ICPC Asia Regional Online —— Warmup

#include  
#include  
#include  
#include  
#include  
#include  
#include  
#include  
#include  
#define INF 99999999  
using namespace std;  
  
const int MAX=1000000+10;  
bool prime[MAX];  
int s[200]={2},size;  
  
void Prime(){//素数筛选   
    for(int i=2;2*i0 n:-n;  
        for(i=0;i<=size;++i){  
            if(!prime[s[i]+m])break;  
        }  
        if(n>0)printf("%d %d\n",s[i]+m,s[i]);  
        else printf("%d %d\n",s[i],s[i]+m);  
    }  
    return 0;  
}