求最大公约数和小于n的所有质数

//algorithm.h

enum SWAP_TYPE{MEMORY, COMPLEX};

struct SIntArray

{

    int *pData;

    int  num;

    SIntArray():pData(NULL),num(0){}

    void Clear(){delete pData; pData = NULL; num = 0;}

};

void      Wswap(int &m, int &n, SWAP_TYPE name = MEMORY);

int       Wgcd(int m, int n);

SIntArray Wprime(int m);



//algorithm.cpp

void Wswap(int &m, int &n, SWAP_TYPE name)//交换

{

    switch(name)

    {

    case MEMORY:

        m = m + n;

        n = m - n;

        m = m - n;

        break;

    case COMPLEX:

        int temp = m;

        m = n;

        n = temp;

        break;

    }

}



int GCD(int m, int n)

{



    if( n == 0)

    {

        return m;

    }

    else

    {

        int r = m % n;

        GCD(n, r);

    }

}



int Wgcd(int m, int n)//寻找最大公约数

{

    if(m > n)

    {

        Wswap(m, n);//make sure m > n    

    }

    int result = GCD(m, n);

    return result;

}



SIntArray Wprime(int m)//找所有小于m的质数

{

    SIntArray result;

    if(m <= 0)

    {

        return result;

    }

    int *number = new int [m+1];

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

    {

        number[i] = i;

    }



    int limit = sqrt((float)m);

    for(int j = 2; j <= limit; j++)

    {

        if(number[j] != 0)

        {

            int temp = j*j;// j 2*j (j-1)*j 1:(j-1) have been processed, so only process j ... n/j


            while(temp <= m) // eliminate

            {

                number[temp] = 0;

                temp = temp + j;                

            }

        }

    }

    int count = 0;

    for(int j = 2; j <= m; j++)

    {

        if(number[j])

        {

            number[count] = number[j];

            count++;

        }

    }

    int *out = new int [count];

    memcpy(out, number, count*sizeof(int));

    delete number;

    number = NULL;



    result.pData = out;

    result.num = count;



    return result;

}


//main.cpp

int _tmain(int argc, _TCHAR* argv[])

{

/*  Wgcd    最大公约数

    int m,n;

    cout<<"input two number:"<<endl;

    cin>>m>>n;

    cout<<"greatest common divisor:"<<endl;

    cout<<Wgcd(m, n)<<endl;

*/

    int m; //小于n的所有质数

    cout<<"input one number:"<<endl;

    cin>>m;

    cout<<"prime number:"<<endl;

    SIntArray result;

    result = Wprime(m);

    for(int i = 0; i <result.num; i++)

    {

        cout<<result.pData[i]<<" ";

    }

    result.Clear();



    return 0;

}