Cod sursa(job #3311435)

Utilizator Gabriel_DaescuDaescu Gabriel Florin Gabriel_Daescu Data 22 septembrie 2025 11:48:52
Problema Al k-lea termen Fibonacci Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.03 kb
#include <fstream>
#define MOD 666013
using namespace std;
ifstream  fin("kfib.in");
ofstream fout("kfib.out");
long long K,Z[2][2],Ans[2][2];

void inmultire_matrice(long long m1[2][2], long long m2[2][2])
{
    long long sol[2][2];

    for(int i=0; i<2; i++)
    {
        for(int j=0; j<2; j++)
        {
            sol[i][j]=0;
            for(int k=0; k<2; k++)
            {
                sol[i][j]=(sol[i][j]+(m1[i][k]*m2[k][j])%MOD)%MOD;
            }
        }
    }

    for(int i=0; i<2; i++)
    {
        for(int j=0; j<2; j++)
        {
            m1[i][j]=sol[i][j];
        }
    }
}

void fast_exp(long long exp)
{
    Ans[0][0]=0;
    Ans[0][1]=Ans[1][0]=Ans[1][1]=1;

    while(exp>0)
    {
        if(exp%2==1)
        {
            inmultire_matrice(Ans,Z);
        }

        inmultire_matrice(Z,Z);
        exp=exp/2;
    }
}

int main()
{
    fin>>K;

    Z[0][0]=0;
    Z[0][1]=Z[1][0]=Z[1][1]=1;

    fast_exp(K-1);

    fout<< Ans[1][0] << "\n";

    return 0;
}