Cod sursa(job #2735153)

Utilizator dariadragomir23Dragomir Daria dariadragomir23 Data 1 aprilie 2021 21:20:56
Problema Al k-lea termen Fibonacci Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.01 kb
#include <fstream>
using namespace std;
ifstream f("kfib.in");
ofstream g("kfib.out");
long long a[3][3], z[3][3], initial[3][3];
int n, MOD=666013;
void inmultire(long long a[3][3], long long b[3][3])
{
    long long rez[3][3];
    for(int i=0; i<=1; i++)
        for(int j=0; j<=1; j++)
        {
            rez[i][j]=0;
            for(int k=0; k<=1; k++)
                rez[i][j]+=a[i][k]*b[k][j];
            rez[i][j]%=MOD;
        }
    for(int i=0; i<=1; i++)
        for(int j=0; j<=1; j++)
            a[i][j]=rez[i][j];
}
void ridicare_putere(long long initial[3][3], int n)
{
    while(n)
    {
        if(n%2==1)
        {
            inmultire(initial,z);
            n--;
        }
        else
        {
            inmultire(z,z);
            n/=2;
        }
    }
}
int main()
{
    f>>n;
    a[0][1]=1;
    z[0][1]=z[1][0]=z[1][1]=1;
    initial[0][0]=initial[1][1]=1;
    ridicare_putere(initial, n);
    inmultire(a, initial);
    g<<a[0][0];
    return 0;
}