Cod sursa(job #1496231)

Utilizator andreiudilaUdila Andrei andreiudila Data 4 octombrie 2015 17:04:06
Problema Al k-lea termen Fibonacci Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.11 kb
#include <fstream>
using namespace std;
ifstream fin("kfib.in");
ofstream fout("kfib.out");

struct matrice{
long long a[4][4];
};

matrice m;
long long x,n,i,j,mod=666013,k;

matrice matr(matrice a, matrice b)
{
        matrice rez;
        for(i=1;i<=2;i++)
            for(j=1;j<=2;j++)
                rez.a[i][j]=0;

        for(i=1;i<=2;i++)
            for(j=1;j<=2;j++)
                for(k=1;k<=2;k++)
                    rez.a[i][j]=((rez.a[i][j])%mod+(a.a[i][k]*b.a[k][j])%mod)%mod;
    return rez;
}

matrice putere(matrice m, int n)
{
    matrice p;
    for(i=1;i<=2;i++)
        for(j=1;j<=2;j++)
            p.a[i][j]=0;
    for(i=1;i<=2;i++) p.a[i][i]=1;

    while(n>0)
    {
        if(n%2==0)
        {
        m=matr(m,m);
        n=n/2;
        }
        else
        {
            p=matr(p,m);
            n--;
        }


    }
 return p;
}

int main()
{
    fin>>n;

        m.a[1][1]=0;
        m.a[1][2]=1;

        m.a[2][1]=1;
        m.a[2][2]=1;


        m=putere(m, n-2);


        fout<<(m.a[1][2]+m.a[2][2])%mod;


    return 0;
}