Cod sursa(job #1894134)

Utilizator saba_alexSabadus Alex saba_alex Data 26 februarie 2017 15:27:10
Problema Al k-lea termen Fibonacci Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 0.85 kb
#include <iostream>
#include <fstream>

using namespace std;

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

const int MOD = 666013;
int n;

struct matrix{

    long long m[2][2];
    void operator *= (const matrix &a){

        matrix c;
        for(int i = 0; i < 2; ++i)
            for(int j = 0; j < 2; ++j){
                c.m[i][j] = 0;
                for(int k = 0; k < 2; ++k)
                    c.m[i][j] += m[i][k] * a.m[k][j];
                c.m[i][j] %= MOD;
            }
        for(int i = 0; i < 2; ++i)
            for(int j = 0; j < 2; ++j)
                m[i][j] = c.m[i][j];
    }
};

matrix r = {0, 1, 1, 1}, t = {1, 1, 0, 0};

int main()
{
    fin >> n;

    for(int s = 1; s <= n; s <<= 1){
        if(n & s)
            t *= r;
        r *= r;
    }

    fout << t.m[0][1];

    return 0;
}