Cod sursa(job #1243129)

Utilizator vazanIonescu Victor Razvan vazan Data 15 octombrie 2014 16:54:24
Problema Al k-lea termen Fibonacci Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1 kb
#include<cstdio>
#include<cstring>
using namespace std;

const int MOD=666013;

class mat
{
    public:
        int ma[2][2];
        mat()
        {
            memset(ma, 0, sizeof(ma));
        }

        void operator*=(const mat& b)
        {
            mat c;
            int i, j, k;
            for(i=0; i<2; ++i)
                for(j=0; j<2; ++j)
                    for(k=0; k<2; ++k)
                        c.ma[i][j]=(c.ma[i][j]+(1LL*ma[i][k]*b.ma[k][j])%MOD)%MOD;
            *this=c;
        }

};

mat pow(mat& a, int b)
{
    mat p;
    p.ma[0][0]=1;
    p.ma[0][1]=0;
    p.ma[1][0]=0;
    p.ma[1][1]=1;
    for( ; b; b>>=1)
    {
        if(b&1)
            p*=a;
        a*=a;
    }
    return p;
}

int main()
{
    FILE *in=fopen("kfib.in", "r"),
         *out=fopen("kfib.out", "w");
    int k;
    fscanf(in, "%d", &k);
    mat a;
    a.ma[0][0]=1;
    a.ma[0][1]=1;
    a.ma[1][0]=1;

    a=pow(a, k-1);

    fprintf(out, "%d", a.ma[0][0]);
}