Cod sursa(job #3278755)

Utilizator XxThornadoxXStoica Teodora XxThornadoxX Data 20 februarie 2025 18:08:45
Problema Al k-lea termen Fibonacci Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.1 kb
#include <bits/stdc++.h>
#define MOD 666013

using namespace std;

ifstream fin("kfib.in");
ofstream fout("kfib.out");

void inm(int mat[2][2], int fib[2][2])
{
    int rez[2][2] = {0};

    for(int i = 0; i < 2; i++)
    {
        for(int j = 0; j < 2; j++)
        {
            for(int k = 0; k < 2; k++)
            {
                rez[i][j] = (rez[i][j] + 1LL*mat[i][k]*fib[k][j])%MOD;
            }
        }
    }

    for(int i = 0; i < 2; i++)
        for(int j = 0; j < 2;j++)
            fib[i][j] = rez[i][j];
}

void pow(int mat[2][2], int e)
{
    int rez[2][2] = {{1,0}, {0,1}};
    while(e)
    {
        if(e%2)
        {
            inm(mat, rez);
        }

        inm(mat, mat);
        e /= 2;
    }

    for(int i = 0; i < 2; i++)
        for(int j = 0; j < 2; j++)
            mat[i][j] = rez[i][j];
}

int n, mat[2][2] = {{1,1}, {1,0}}, fib[2][2] = {{1,0}, {0,0}};

int main()
{
    fin >> n;

    if(n == 0)
    {
        fout << 0;
        return 0;
    }

    pow(mat, n-1);
    inm(mat, fib);

    fout << fib[0][0];
    return 0;
}