Cod sursa(job #1165314)

Utilizator Barcau_EmanuelBarcau Emanuel Barcau_Emanuel Data 2 aprilie 2014 17:03:06
Problema Al k-lea termen Fibonacci Scor 60
Compilator cpp Status done
Runda Arhiva educationala Marime 0.85 kb
#include <iostream>
#include <fstream>
#include <cstring>
using namespace std;
ifstream f("kfib.in");
ofstream g("kfib.out");
int rez[2][2],a[2][2],n;

void mul(int ac[2][2], int b[2][2])
{
    int i,j,k;
    for(i=0;i<2;i++)
        for(j=0;j<2;j++)
        {
            rez[i][j]=0;
            for(k=0;k<2;k++)
                {
                    rez[i][j]+=((long long)ac[i][k]*(long long)b[k][j])%666013;
                }
        }

    memcpy(ac,rez,sizeof(rez));
}

void pow(int aa[2][2], int n)
{
    int p[2][2];
    p[0][0]=p[0][1]=p[1][0]=1;
    p[1][1]=0;
    while(n)
    {
        if(n&1)
            mul(p,aa);
        mul(aa,aa);
        n=n>>1;
    }
    memcpy(aa,p,sizeof(aa));
}

int main()
{
    a[0][0]=a[0][1]=a[1][0]=1;
    a[1][1]=0;
    f>>n;
    pow(a,n-2);
    g<<a[0][0]<<"\n";
    return 0;
}