Cod sursa(job #2048013)

Utilizator BogdanNeghinaNeghina Bogdan BogdanNeghina Data 25 octombrie 2017 18:17:39
Problema Al k-lea termen Fibonacci Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.98 kb
#include <fstream>
#define mod 666013
using namespace std;
ifstream cin("kfib.in");
ofstream cout("kfib.out");
int n,b[3][3],a[3][3]={{0,0,0},{0,1,1},{0,1,0}};
void cp(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 prod(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 t=1;t<=2;t++)
                c[i][j]=(c[i][j]+(1ll*a[i][t]*b[t][j])%mod)%mod;
        }
}
void p(int x[3][3], int b[3][3],int n)
{
    int c[3][3];
    if(n==1)
    {
        cp(b,x);
        return;
    }
    p(x,c,n/2);
    prod(c,c,b);
    if(n%2==1)
    {
        prod(b,a,c);
        cp(b,c);
    }
}
int main ()
{
    cin>>n;
    if(n==1)
    {
        cout<<1;
        return 0;
    }
    if(n==0)
    {
        cout<<0;
        return 0;
    }
    p(a,b,n-1);
    cout<<b[1][1]%mod;
    return 0;
}