HDU 2281 Square Number Pell方程

http://acm.hdu.edu.cn/showproblem.php?pid=2281

又是一道Pell方程

化简构造以后的Pell方程为

求出其前15个解,但这些解不一定满足等式,判断后只有5个满足的情况,直接判断即可

求法可以参照上一篇日志: http://www.cnblogs.com/Felix-F/p/3223323.html

struct matrix
{
    LL ma[][];
};
int n = ;
LL nn[],xx[];
matrix operator * (matrix a,matrix b)
{
    matrix temp;
    memset(temp.ma,,sizeof(temp.ma));
    for(int i = ; i < n ; i++)
        for(int j = ; j < n ; j++)
            for(int k =  ; k < n ; k++)
                temp.ma[i][j] = temp.ma[i][j] + (a.ma[k][i] * b.ma[j][n-k-]);
    return temp;
}
matrix operator + (matrix a,matrix b)
{
    for(int i = ; i < n ; i++)
        for(int j = ; j < n ; j++)
            a.ma[i][j] = (a.ma[i][j] + b.ma[i][j]) ;
    return a;
}
void init()
{
    matrix a;
    a.ma[][] = ;
    a.ma[][] = ;
    a.ma[][] = ;
    a.ma[][] = ;
    matrix temp = a;
    nn[] = ;
    xx[] = ;
    int cnt = ;
    for(int i =  ;i <=  ; i++)
    {
        if(i% == )
        {
            LL s1 = temp.ma[][] *  + temp.ma[][] * ;
            nn[cnt] = (s1 - ) / ;
            LL s2 = temp.ma[][] *  + temp.ma[][] * ;
            xx[cnt++] = s2;
        }
        temp = temp*a;
    }
}
int main()
{
    init();
    LL N;
    while(cin>>N && N)
    {
        for(int i =  ; i >=  ; i--)
        {
            if(N >= nn[i])
            {
                cout<<nn[i]<<" "<<xx[i]<<endl;
                break;
            }
        }
    }
    return ;
}