Cod sursa(job #3123728)

Utilizator Robert_MitriRobert Mitri Robert_Mitri Data 25 aprilie 2023 09:55:25
Problema Al k-lea termen Fibonacci Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.97 kb
#include <fstream>
#define mod 666013
using namespace std;
ifstream fin("kfib.in");
ofstream fout("kfib.out");

int n;

long long b[2][2];


void prod(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]%=mod;
            }
        }
    }
}
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];
        }
    }
}


int main()
{
    fin>>n;
    long long a[2][2]={{1,1},{1,0}};
    long long c[2][2]={{1,0},{0,1}};

    n-=2;
    while(n)
    {
        if(n%2)
        {
            prod(c,a,b);
            copy_(c,b);
        }
        n/=2;
        prod(a,a,b);
        copy_(a,b);

    }
    fout<<(c[0][0]+c[0][1])%mod;
}