Cod sursa(job #1684014)

Utilizator GinguIonutGinguIonut GinguIonut Data 10 aprilie 2016 18:38:47
Problema Al k-lea termen Fibonacci Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.02 kb
#include <fstream>
#include <string.h>

#define MOD 666013
using namespace std;
ifstream fin("kfib.in");
ofstream fout("kfib.out");
int n;
int SOL[2][2], MAT[2][2];
void read()
{
    fin>>n;

    MAT[0][0]=0, MAT[0][1]=1, MAT[1][0]=1, MAT[1][1]=1;
}
void mult(int A[][2], int B[][2], int C[][2])
{
    for(int i=0;i<2;i++)
        for(int j=0;j<2;j++)
            for(int k=0;k<2;k++)
                C[i][j]=(C[i][j] + 1LL*A[i][k]*B[k][j])%MOD;
}
void lg_power(int M[][2], int exp)
{
    int C[2][2], AUX[2][2];
    memcpy(C, MAT, sizeof(C));
    M[0][0]=M[1][1]=1;

    for(int i=0;(1 << i)<=exp;i++)
    {
        if((1 << i) & exp)
        {
            memset(AUX, 0, sizeof(AUX));
            mult(M, C, AUX);
            memcpy(M, AUX, sizeof(AUX));
        }
        memset(AUX, 0, sizeof(AUX));
        mult(C, C, AUX);
        memcpy(C, AUX, sizeof(AUX));
    }
}
void write()
{
    fout<<SOL[1][1];
}
int main()
{
    read();
    lg_power(SOL, n-1);
    write();
    return 0;
}