Cod sursa(job #1899199)

Utilizator BogdanNeghinaNeghina Bogdan BogdanNeghina Data 2 martie 2017 16:25:24
Problema Al k-lea termen Fibonacci Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.05 kb
#include <fstream>
#define mod 666013
using namespace std;
ifstream cin("kfib.in");
ofstream cout("kfib.out");
int a[3][3]={{0,0,0},{0,1,1},{0,1,0}},n,b[3][3];
void inmultire(int a[3][3],int b[3][3], int c[3][3])
{
    for(int i=1;i<=2;i++)
        for(int j=1;j<=2;j++)
        {
            c[i][j]=0;
            for(int k=1;k<=2;k++)
                c[i][j]=(c[i][j]+(1ll*a[i][k]*b[k][j])%mod)%mod;
        }
}
void copiaza (int a[3][3],int b[3][3])
{
    for(int i=1;i<=2;i++)
        for(int j=1;j<=2;j++)
            a[i][j]=b[i][j];
}
void putere(int x[3][3], int b[3][3],int n)
{
    int c[3][3];
    if(n==1)
    {
        copiaza(b,x); // b=a;
        return;
    }
    putere(x,c,n/2);
    inmultire(c,c,b);//c*c=b
    if(n%2==1)
       {
           inmultire(b,a,c);
           copiaza(b,c);
       }
}
int main ()
{
    cin>>n;
    if(n==0)
    {
        cout<<0;
        return 0;
    }
    if(n==1)
    {
        cout<<1;
        return 0;
    }
    putere(a,b,n-1);
    cout<<b[1][1]%mod;
    return 0;
}