Cod sursa(job #2150067)

Utilizator razvan99hHorhat Razvan razvan99h Data 3 martie 2018 11:32:26
Problema Al k-lea termen Fibonacci Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.02 kb
#include <iostream>
#include <fstream>
#include <string.h>
#define MOD 666013
using namespace std;
ifstream fin("kfib.in");
ofstream fout("kfib.out");

int a[2][2] = {
    {0, 1},
    {1, 1}
};
int ret[2][2] = {
        {1, 0},
        {0, 1}
};
int n, c[2][2];

inline void matmult(int a[2][2], int b[2][2], int c[2][2])
{
    for(int i = 0; i < 2; i++)
        for(int j = 0; j < 2; j++)
        {
            c[i][j] = 0;
            for(int k = 0; k < 2; k++)
                c[i][j] =(c[i][j] + (1LL * a[i][k] * b[k][j]) % MOD) % MOD;
        }
}
inline int fib_lgput(int n) // ridicam matricea constanta a la puterea n-1 si obtinem al n-ulea termen al sirului lui fib
{
    n--;
    while(n)
    {
        if(n % 2 == 1)
        {
            matmult(a, ret, c);
            memcpy(ret, c, sizeof(ret));
        }
        matmult(a, a, c);
        memcpy(a, c, sizeof(a));
        n /= 2;
    }
    return ret[1][1];
}
int main()
{
    fin >> n;
    fout << fib_lgput(n);
    return 0;
}