Cod sursa(job #2271636)

Utilizator CristyXtremeSimion Cristian CristyXtreme Data 28 octombrie 2018 23:45:41
Problema Al k-lea termen Fibonacci Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.17 kb
#include <stdio.h>
#define mod 666013

using namespace std;

struct matrice {long long int m[2][2];};

matrice inmultire_matrice(matrice a, matrice b) {
    matrice c;
    for (int i = 0; i < 2; i++)
        for (int j = 0; j < 2; j++)
            c.m[i][j] = 0;
    for (int i = 0; i < 2; i++)
        for (int j = 0; j < 2; j++)
            for (int k = 0; k < 2; k++)
                c.m[i][j] = (c.m[i][j] + a.m[i][k] * b.m[k][j]) % mod;
    return c;
}

void lgput(matrice &a, long long int x) {
    matrice sol, exp = a;
    sol.m[0][1] = sol.m[1][0] = 0;
    sol.m[0][0] = sol.m[1][1] = 1;
    while (x) {
        if (x & 1)
            sol = inmultire_matrice(sol, exp);
        exp = inmultire_matrice(exp, exp);
        x >>= 1;
    }
    a = sol;
}

int main()
{
    int k;
    freopen("kfib.in", "r", stdin);
    freopen("kfib.out", "w", stdout);
    scanf("%d", &k);
    if (k == 0) {
        printf("0");
        return 0;
    }
    matrice recurenta;
    recurenta.m[0][0] = recurenta.m[0][1] = recurenta.m[1][0] = 1;
    recurenta.m[1][1] = 0;
    lgput(recurenta, k - 1);
    printf("%d\n", recurenta.m[0][0] % mod);
    return 0;
}