Cod sursa(job #3219050)

Utilizator gianiferSpita Alexandru-Mihai gianifer Data 29 martie 2024 20:17:36
Problema Al k-lea termen Fibonacci Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.39 kb
#include <bits/stdc++.h>
#define MOD 666013
using namespace std;

ifstream fin("kfib.in");

ofstream fout("kfib.out");
int n;
unsigned long long rez[2][2] = {1, 1,
                                1, 0};
unsigned long long z[2][2] = {1, 1,
                              1, 0};
unsigned long long rez1[2][2];
void inmultire(unsigned long long a[][2], unsigned long long b[][2])
{
    rez1[0][0] = (((a[0][0] * b[0][0]) % MOD) + (a[0][1] * b[1][0]) % MOD) % MOD;
    rez1[0][1] = (((a[0][0] * b[0][1]) % MOD) + (a[0][1] * b[1][1]) % MOD) % MOD;
    rez1[1][0] = (((a[1][0] * b[0][0]) % MOD) + (a[1][1] * b[1][0]) % MOD) % MOD;
    rez1[1][1] = (((a[1][0] * b[0][1]) % MOD) + (a[1][1] * b[1][1]) % MOD) % MOD;
}
void copiere()
{
    for (int i = 0; i <= 1; i++)
        for (int j = 0; j <= 1; j++)
            rez[i][j] = rez1[i][j];
}
void inmultire_log(int k)
{
    if (k == 1)
        return;
    else
    {
        inmultire_log(k / 2);
        if (k % 2 == 0)
        {
            inmultire(rez, rez);
            copiere();
        }
        else
        {
            inmultire(rez, rez);
            copiere();
            inmultire(rez, z);
            copiere();
        }
    }
}
int main()
{
    fin >> n;
    if (n == 1 || n == 2)
    {
        fout << 1;
        return 0;
    }
    inmultire_log(n);

    fout << (rez[0][0] + (MOD - rez[1][1])) % MOD;
}