Cod sursa(job #3357397)

Utilizator malita.dragosMalita Dragos-Ionut malita.dragos Data 9 iunie 2026 12:09:38
Problema Al k-lea termen Fibonacci Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.94 kb
#include <fstream>

#define NR 666013

using namespace std;

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

int I[2][2] = {{0,1},{1,1}};
int M1[1][2] = {{0,1}};
int z[2][2];

void in_mat(int a[][2],int b[][2],int c[][2]){
    int t[2][2] = {0};
    for(int i=0;i<2;i++){
        for(int j=0;j<2;j++){
            for(int k=0;k<2;k++){
                t[i][j] = (t[i][j] + 1LL*a[i][k] * b[k][j])%NR;
            }
        }
    }
    for(int i=0;i<2;i++)
        for(int j=0;j<2;j++)
        c[i][j] = t[i][j];
}

void exp(int z[][2],int P){
    if(P == 0){
        z[0][0]=1,z[0][1]=0,z[1][0]=0,z[1][1]=1;
        return;
    }
    exp(z,P/2);
    in_mat(z,z,z);
    if(P%2 != 0){
        in_mat(z,I,z);
    }
}

int main()
{
    int K;
    fin>>K;
    if(K == 0 || K == 1){
        fout<<K;
        return 0;
    }
    exp(z,K-1);

    fout<<(M1[0][0]*z[0][1] + M1[0][1]*z[1][1])%NR;

    return 0;
}