Cod sursa(job #2215386)

Utilizator dia.ionescuIonescu Diana dia.ionescu Data 21 iunie 2018 21:33:24
Problema Al k-lea termen Fibonacci Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.27 kb
#include <iostream>
#include <fstream>
#define mod 666013
using namespace std;

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

void inmult(long long a[3][3], long long b[3][3], long long c[3][3]) {
    int i, j, k;
    for (i = 0; i < 2; i++)
        for (j = 0; j < 2; j++)
            for (k = 0; k < 2; k++)
                c[i][j] = (c[i][j] + (a[i][k] * b[j][k]) % mod) % mod;
}

void init(long long a[3][3]) {
    for (int i = 0; i < 2; i++)
        for (int j = 0; j < 2; j++)
            a[i][j] = 0;
}

void mut(long long a[3][3], long long b[3][3]) {
    for (int i = 0; i < 2; i++)
        for (int j = 0; j < 2; j++)
            a[i][j] = b[i][j] % mod;
}

int pow(int p, long long Z[3][3]) {
    long long sol[3][3], aux[3][3];
    init(aux);
    init(sol);
    sol[0][0] = 1;
    sol[1][1] = 1;
    while (p) {
        if (p % 2 == 1) {
            init(aux);
            inmult(Z, sol, aux);
            mut(sol, aux);
            p--;
        }
        init(aux);
        inmult(Z, Z, aux);
        mut(Z, aux);
        p = p / 2;
    }
    return sol[1][1] % mod;
}

int main()
{
    long long Z[3][3], k;
    fin >> k;
    Z[0][0] = 0;
    Z[0][1] = 1;
    Z[1][0] = 1;
    Z[1][1] = 1;

   fout << pow(k - 1, Z);
}