Cod sursa(job #3322079)

Utilizator Luca_ManguciManguci Luca-George Luca_Manguci Data 12 noiembrie 2025 17:41:17
Problema Al k-lea termen Fibonacci Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.92 kb
#include <fstream>
using namespace std;

const int MOD = 666013;

int A[2][2] = { {1, 1}, {1, 0} };
int I[2][2] = { {1, 0}, {0, 1} };

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

void multmat(int a[][2], int b[][2])
{
    long long c[2][2];
    int i, j, k;

    for (i = 0; i < 2; i++)
        for (j = 0; j < 2; j++)
        {
            c[i][j] = 0;
            for (k = 0; k < 2; k++)
                c[i][j] += 1LL * a[i][k] * b[k][j];
        }

    for (i = 0; i < 2; i++)
        for (j = 0; j < 2; j++)
            a[i][j] = c[i][j] % MOD;
}

void puteremat(int p)
{
    while (p)
    {
        if (p & 1)
            multmat(I, A);
        multmat(A, A);
        p >>= 1;
    }
}

int main()
{
    int k;
    f >> k;

    if (k <= 1)
        g << k;
    else
    {
        puteremat(k - 1);
        g << I[0][0];
    }

    f.close();
    g.close();
    return 0;
}