Cod sursa(job #3124464)

Utilizator AlexanderCernyCernaianu Alexandru AlexanderCerny Data 28 aprilie 2023 20:27:54
Problema Al k-lea termen Fibonacci Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.02 kb
#include <fstream>
#define mod 666013

using namespace std;

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

void copiere(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 produs(long long a[2][2],long long b[2][2],long long c[2][2])
{
    int i,j,k;
    for(i=0;i<=1;i++)
        for(j=0;j<=1;j++)
        {
            c[i][j]=0;
            for(k=0;k<=1;k++)
            {
                c[i][j]+=a[i][k]*b[k][j];
                c[i][j]%=mod;
            }
        }
}
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)
        {
            produs(p,a,b);
            copiere(p,b);
        }
        produs(a,a,b);
        copiere(a,b);
        n/=2;
    }
    fout<<(p[0][0]+p[0][1])%mod;
    return 0;
}