Cod sursa(job #3173822)

Utilizator AlbertPavPavalache Albert AlbertPav Data 23 noiembrie 2023 19:12:46
Problema Al k-lea termen Fibonacci Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.85 kb
#include <iostream>
#include <fstream>
#include <cstring>
using namespace std;
const int MOD = 666013;

int A[2][2] = {{1, 1}, {1, 0}},
I[2][2] = {{1, 0}, {0, 1}};

ifstream f("kfib.in");
ofstream g("kfib.out");

void multmat(int a[][2], int b[][2])
{
    int c[2][2], 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]=(c[i][j]+1LL*a[i][k]*b[k][j])%MOD;
        }
    memcpy(a,c,sizeof(c));
}

void puteremat(int p)
{
    while(p)
    {
        if(p & 1)
            multmat(I, A);
        multmat(A, A);
        p >>= 1;
    }
}

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;
}