bool test(int n){
--n;
// test that its two least significant digits are 01
if( !(n & 0x1) && ( (n>>1) & 0x1) ){
// factor
std::vector<int> divs( getDivisors(n) );
std::vector<int>::iterator it;
for(it = divs.begin(); it != divs.end(); it++){
if( !g_primes.isPrime(*it + n/(*it)) ){
return false;
}
}
return true;
}
else{
return false;
std::vector< std::pair<int, int> > getFactors(int n){
std::vector< std::pair<int, int> > factors;
int p = 2;
do{
int multiplicity = 0;
while( n % p == 0 ){
multiplicity++;
n /= p;
}
if( multiplicity ){
factors.push_back( std::make_pair(p, multiplicity) );
}
if( g_primes.isPrime(n) ){
factors.push_back( std::make_pair(n, 1) );
break;
}
} while( (n > 1) && (p = g_primes.nextPrime(p)) );
return factors;
}
