UVa 10394 Twin Primes (twin primes)

10394-twin Primes

Time limit:3.000 seconds

Http://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=24&page=show_problem &problem=1335

Twin primes are pairs of primes of the form (p, p+2). The term "twin prime" was coined by Paul Stckel (1892-1919). The the few twin primes are (3, 5), (5, 7), (11, 13), (17, 19), (29, 31), (41, 43). In this problem your are asked to find out the s-th twin prime pair Where's is a integer that would be given in the input.

Input

The input would contain less than 10001 lines of input. Each line contains a integers S (1<=s<=100000), which is the serial number of a twin prime. The Input file is terminated by the end of file.

Output

For each line of input you'll have to produce one line of output which contains the s-th twin prime. The pair is printed in the form (P1,<SPACE>P2). Here <space> means the "space character" (ASCII 32). You can safely assume this primes in 100000-th twin prime pair are less than 20000000.

Sample Input
1

2

3

4

Sample Output
(3, 5)

(5, 7)

(11, 13)

(17, 19)

Water problem.

Complete code:

/*0.342s*/
    
#include <cstdio>  
const int MAXN = 20000000;  
    
BOOL VIS[MAXN];  
int PRIME[MAXN/10], C, twinprime[100005];  
    
/* with I as the benchmark sieve composite
//*o (MAXN) Time complexity */
void Cal_prime ()  
{for  
    (int i = 2; i < MAXN; ++i)  
    {  
        if!vis[ I]) prime[c++] = i;  
        for (int j = 0; J < c && I * Prime[j] < MAXN ++j)  
        {  
            vis[i * prime[j]] = true;  
            if (i% prime[j] = = 0) break  
        ;  
    
}} /* Determine the twin prime number
/inline void judge ()  
{  
    int i, J;  
    for (i = 3, j = 1; J <= 100000 i + + 2)  
        if (!vis[i] &&!vis[i + 2])  
            twinprime[j++] = i;  
}  
    
int main ()  
{  
    cal_prime ();  
    Judge ();  
    int n;  
    while (~SCANF ("%d", &n))  
        printf ("(%d,%d) \ n", Twinprime[n], Twinprime[n] + 2);  
    return 0;  
}

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