Cod sursa(job #3341373)

Utilizator Sabin1133Padurariu Sabin Sabin1133 Data 19 februarie 2026 11:46:09
Problema Al k-lea termen Fibonacci Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.41 kb
#include <iostream>

#define MOD 666013U

int main()
{
    int n;
    long unit[2][2] = {{0, 1}, {1, 1}}, tmp[2][2], prod[2][2] = {{1, 0}, {0, 1}};

    freopen("kfib.in", "r", stdin);
    freopen("kfib.out", "w", stdout);

    std::cin >> n;

    if (n == 0)
        prod[1][1] = 0;
    else if (n == 1)
        prod[1][1] = 1;
    else
        for (int e = 1; e <= n - 1; e <<= 1) {
            if ((n - 1) & e) {
                tmp[0][0] = (unit[0][0] * prod[0][0] + unit[0][1] * prod[1][0]) % MOD;
                tmp[0][1] = (unit[0][0] * prod[0][1] + unit[0][1] * prod[1][1]) % MOD;
                tmp[1][0] = (unit[1][0] * prod[0][0] + unit[1][1] * prod[1][0]) % MOD;
                tmp[1][1] = (unit[1][0] * prod[0][1] + unit[1][1] * prod[1][1]) % MOD;

                for (int i = 0; i < 2; ++i)
                    for (int j = 0; j < 2; ++j)
                        prod[i][j] = tmp[i][j];
            }

            tmp[0][0] = (unit[0][0] * unit[0][0] + unit[0][1] * unit[1][0]) % MOD;
            tmp[0][1] = (unit[0][0] * unit[0][1] + unit[0][1] * unit[1][1]) % MOD;
            tmp[1][0] = (unit[1][0] * unit[0][0] + unit[1][1] * unit[1][0]) % MOD;
            tmp[1][1] = (unit[1][0] * unit[0][1] + unit[1][1] * unit[1][1]) % MOD;

            for (int i = 0; i < 2; ++i)
                for (int j = 0; j < 2; ++j)
                    unit[i][j] = tmp[i][j];
        }

    std::cout << prod[1][1] << '\n';

    return 0;
}