Cod sursa(job #2608198)

Utilizator bl1nk3rFilip Corlan bl1nk3r Data 30 aprilie 2020 19:13:27
Problema Al k-lea termen Fibonacci Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.06 kb
#include <iostream>
#include <fstream>

using namespace std;

typedef unsigned long long lint;

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

const lint N = 2;
const lint MOD = 666013;

void mat_mul(lint p[N][N], lint a[N][N], lint b[N][N]) {
    lint aux[N][N];

    for (lint i = 0; i < N; i++) {
        for (lint j = 0; j < N; j++) {
            aux[i][j] = 0;
            for (lint k = 0; k < N; k++) {
                aux[i][j] += ((a[i][k] % MOD) * (b[k][j] % MOD)) % MOD;
                aux[i][j] %= MOD;
            }
            aux[i][j] %= MOD;
        }
    }

    for (lint i = 0; i < N; i++) {
        for (lint j = 0; j < N; j++) {
            p[i][j] = aux[i][j];
        }
    }
}

int main() {
    lint n;
    in >> n;

    lint p[N][N] = {{1, 1}, {1, 0}};
    lint a[N][N] = {{1, 0}, {0, 1}};

    if (!n) a[0][0] = 0;

    n--;

    while (n != 0) {
        if (n % 2 != 0) {
            mat_mul(a, a, p);
        }

        mat_mul(p, p, p);
        n /= 2;
    }

    out << a[0][0];

    return 0;
}