Cod sursa(job #3187477)

Utilizator not_anduAndu Scheusan not_andu Data 29 decembrie 2023 09:42:57
Problema Al k-lea termen Fibonacci Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.35 kb
/**
 * Author: Andu Scheusan (not_andu)
 * Created: 29.12.2023 09:24:45
*/

#include <bits/stdc++.h>
#pragma GCC optimize("O3")

using namespace std;

#define INFILE "kfib.in"
#define OUTFILE "kfib.out"

typedef long long ll;

const int MOD = 666013;

typedef vector<vector<ll> > Matrix;

Matrix IDN(2, vector<ll>(2, 0));

Matrix matMultiply(Matrix a, Matrix b){
    Matrix ans(a.size(), vector<ll>(b[0].size(), 0));
    for(int i = 0; i < ans.size(); ++i){
        for(int j = 0; j < ans[i].size(); ++j){
            for(int k = 0; k < b.size(); ++k){
                ans[i][j] = (ans[i][j] % MOD + ((a[i][k] % MOD) * (b[k][j] % MOD)) % MOD) % MOD;
            }
        }
    }
    return ans;
}

Matrix matPower(Matrix a, int exponent){
    Matrix ans = IDN;
    while(exponent){
        if(exponent & 1) ans = matMultiply(ans, a);
        a = matMultiply(a, a);
        exponent >>= 1;
    }
    return ans;
}

void solve(){

    ll n; cin >> n;

    IDN[0][0] = IDN[1][1] = 1;

    Matrix m(2, vector<ll>(2, 1));
    m[1][1] = 0;
    Matrix ans(2, vector<ll>(1, 0));
    ans[0][0] = 1;

    m = matPower(m, n);
    ans = matMultiply(m, ans);

    cout << ans[1][0] << '\n';

}

int main(){
    
    ios_base::sync_with_stdio(false);

    freopen(INFILE, "r", stdin);
    freopen(OUTFILE, "w", stdout);

    cin.tie(nullptr);
    cout.tie(nullptr);

    solve();

    return 0;
}