Cod sursa(job #3123813)

Utilizator AnaGrigorieAna Teodora Grigorie AnaGrigorie Data 25 aprilie 2023 16:13:12
Problema Al k-lea termen Fibonacci Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.07 kb
#include <fstream>

using namespace std;

ifstream fin("kfib.in");
ofstream fout("kfib.out");

void copy(long long a[2][2], long long b[2][2])
{
    for(int i=0;i<=1;i++)
    {
        for(int j=0;j<=1;j++)
        {
            a[i][j]=b[i][j];
        }
    }
}
void inmultire_matrici(long long a[2][2],long long b[2][2], long long c[2][2])
{
    for(int i=0;i<=1;i++)
    {
        for(int j=0;j<=1;j++)
        {
            c[i][j]=0;
            for(int k=0;k<=1;k++)
            {
                c[i][j]+=a[i][k]*b[k][j];
                c[i][j]%=666013;
            }
        }
    }
}
int n;
int main()
{
    fin>>n;
    if(n<=2)
    {
        fout<<1;
        return 0;
    }
    n-=2;
    long long a[2][2]={ {1,1},
                        {1,0} };
    long long p[2][2]={ {1,0},
                        {0,1} };
    long long b[2][2];
    while(n)
    {
        if(n%2==1)
        {
            inmultire_matrici(p,a,b);
            copy(p,b);
        }
        inmultire_matrici(a,a,b);
        copy(a,b);
        n/=2;
    }
    fout<<(p[0][0]+p[0][1])%666013;
    return 0;
}