Cod sursa(job #405696)

Utilizator alexandru92alexandru alexandru92 Data 28 februarie 2010 17:28:11
Problema Suma divizorilor Scor 30
Compilator cpp Status done
Runda Arhiva de probleme Marime 1.09 kb
#include <vector>
#include <fstream>
#include <cstdlib>
#define Modulo 9901
#define Nmax 7079

/*
 *
 */
using namespace std;
typedef long long int lld;
char is_prime[Nmax/16+1];
vector< int > Prime;
void Sieve( void )
{
	unsigned int i, j;
	for( i=1; ( (i*i)<<1 )+(i<<1) <= Nmax; ++i )
		if( 0 == ( is_prime[i>>3] & ( 1<<(i&7) ) ) )
			for( j=((i*i)<<1)+(i<<1); (j<<1)+1 <= Nmax; j+=(i<<1)+1 )
				is_prime[j>>3]|=(1<<(j&7));
	Prime.push_back(2);
	for( i=1; (i<<1)+1 <= Nmax; ++i )
		if( 0 == ( is_prime[i>>3] & ( 1<<(i&7) ) ) )
			Prime.push_back( (i<<1)+1 );
}
inline lld pow( lld x, lld n )
{
	lld r=1;
	for( ; n; n>>=1 )
	{
		if( n&1 )
			r*=x;
		x*=x;
	}
	return r;
}
int main( void )
{
	lld A, B, i, j, s=1;
	ifstream in( "sumdiv.in" );
	in>>A>>B;
	Sieve();
	for( i=0; 1LL*Prime[i]*Prime[i] <= A; ++i )
		if( 0 == A%Prime[i] )
		{
			for( j=0; 0 == A%Prime[i]; ++j, A/=Prime[i] );
			s=( s* ( pow( Prime[i], j*B+1 )-1 )/( Prime[i]-1 ) )%Modulo;
		}
	if( A > 1 )
		s=( s*(pow( A, B+1 )-1 )/( A-1 ) )%Modulo;
	ofstream out( "sumdiv.out" );
	out<<s;
	return 0;
}