矩阵运算

Posted 2020-11-25 wzzyr24

就是来存个板子……

struct matrix
{
    int x,y,num[35][35];
    matrix() : x(0),y(0) {memset(num,0,sizeof(num));}
    matrix operator*(matrix b)
    {
        matrix c;
        c.x=x,c.y=b.y;
        for(int k=1;k<=y;++k)
            for(int i=1;i<=x;++i)
                for(int j=1;j<=b.y;++j)
                    c.num[i][j]=(c.num[i][j]+num[i][k]*b.num[k][j]%m)%m;
        return c;
    }
    matrix operator+(matrix b)
    {
        matrix c;
        c.x=x,c.y=y;
        for(int i=1;i<=x;++i)   
            for(int j=1;j<=y;++j)
                c.num[i][j]=(num[i][j]+b.num[i][j])%m;
        return c;
    }
}a;

matrix qpow(matrix a,int p)
{
    matrix res;
    res.x=a.x,res.y=a.y;
    for(int i=1;i<=res.x;++i) res.num[i][i]=1;
    for(;p;p>>=1)
    {
        if(p&1) res=res*a;
        a=a*a;
    }
    return res;
}