Cod sursa(job #3202955)

Utilizator gabriela15Popescu Gabriela Irina gabriela15 Data 12 februarie 2024 19:11:09
Problema Al k-lea termen Fibonacci Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.96 kb
#include <iostream>
#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>0)
        if(p%2==0)
        {
            multmat(A, A);
            p/=2;
        }
        else
        {
            multmat(I, A);
            p--;
        }
}

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;
}