hdu 1299

这个方法太厉害了 别人的记录一下

#include<iostream>

#include<cstdio>

#include<cstring>

#include<cmath>

#include<algorithm>

#include<bitset>

#include<iomanip>

using namespace std;
#define MAX_PRIME 31700

#define PRIME_NUM 3500
int Primes[ PRIME_NUM + 10 ] ;
int _Count = 0  ;

int GetPrimes( )

{

    unsigned char  *PrimeBuffer = ( unsigned char * ) malloc( sizeof( unsigned char ) * ( MAX_PRIME + 10 ) ) ;

    int i , j  ;
memset( Primes , 0 , sizeof( int ) *PRIME_NUM ) ;

    memset( PrimeBuffer , 0 , sizeof( unsigned char) * MAX_PRIME ) ;
for( i = 2 ; i < MAX_PRIME ; i++ )

    {

        if( PrimeBuffer[ i ] == 0 )

            Primes[ _Count++ ] = i ;

        for( j = 0 ; j < _Count && i * Primes[ j ] <= MAX_PRIME ; j++ )

        {

            PrimeBuffer[ i * Primes[ j ] ] = 1 ;

             if( i % Primes[ j ] == 0 )

                  break ;

        }

    }

    free( PrimeBuffer ) ;

    return _Count ;

}
int main()

{

    GetPrimes();

    int Case , n , num , sum , temp;

    cin >> Case ;

    temp = 0 ;

    while( Case-- )

    {

        cin >> n ;

        sum = 1 ;

        for( int i = 0 ; i < _Count ; ++i )

        {

            int  flag =  ( int )sqrt( n ) + 1 ;

            if( Primes[ i ] > flag )

                break ;

            num = 0 ;

            while( n % Primes[ i ] == 0 )

            {

                num++ ;

                n /= Primes[ i ] ;

            }

            sum *= ( 1 + 2 * num ) ;

        }

        if( n > 1 )

            sum *= 3 ;

        cout << "Scenario #" << ++temp << ":" << endl ;

        cout << ( sum + 1 ) / 2 << endl << endl ;

    }

    return 0 ;

}

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