Cod sursa(job #1212524)

Utilizator mariusn01Marius Nicoli mariusn01 Data 25 iulie 2014 01:34:00
Problema Al k-lea termen Fibonacci Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.03 kb
#include <fstream>
#define MOD 666013
using namespace std;
ifstream fin("kfib.in");
ofstream fout("kfib.out");

void copiere(long long a[2][2], long long b[2][2]) {
    for (int i=0;i<=1;i++)
        for (int j=0;j<=1;j++)
            a[i][j] = b[i][j];
}

void inmultire(long long a[2][2], long long b[2][2], long long c[2][2]) {
    int i, j, k;
    for (i=0;i<=1;i++)
        for (j=0;j<=1;j++) {
            c[i][j] = 0;
            for (k=0;k<=1;k++) {
                c[i][j] += a[i][k] * b[k][j];
                c[i][j] %= MOD;
            }
        }
}

int n;

int main() {
    fin>>n;
    if (n<=2) {
        fout<<1;
        return 0;
    }

    n-=2;
    long long a[2][2] = { {1,1}, {1,0} };
    long long r[2][2] = { {1,0}, {0,1} };
    long long b[2][2];
    while (n) {
        if (n&1) {
            inmultire(r, a, b);
            copiere(r, b);
        }
        inmultire(a, a, b);
        copiere(a, b);

        n/=2;

    }
    fout<<(r[0][0] + r[0][1])%MOD;
    return 0;
}