Cod sursa(job #2489635)

Utilizator VladAdrianaVlad Adriana VladAdriana Data 9 noiembrie 2019 10:23:15
Problema Al k-lea termen Fibonacci Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.85 kb
#include <fstream>
#include <cstring>

using namespace std;
ifstream fin("kfib.in");
ofstream fout("kfib.out");
int n;
struct matrice{int m[2][2];}M,I,R;
matrice Minm(matrice a, matrice b)
{
    matrice ans;
    memset(ans.m,0,sizeof(ans.m));
    for(int i=0;i<2;i++)
        for(int j=0;j<2;j++)
            for(int k=0;k<2;k++)
                ans.m[i][j]=(ans.m[i][j]+1LL*a.m[i][k]*b.m[k][j])%666013;
    return ans;
}
matrice Mpow(matrice M, int n)
{
    if(!n) return I;
    if(n%2==1)
        return Minm(M, Mpow(Minm(M,M),n/2));
    return Mpow(Minm(M,M),n/2);
}
int main()
{
    fin>>n;
    M.m[0][0]=M.m[1][0]=M.m[0][1]=1;
    I.m[0][0]=I.m[1][1]=1;
    if(n<=1) fout<<1<<'\n';
    else
    {
        R.m[0][0]=R.m[1][0]=1;
        ///rez=(m^n)*r;
        R=Minm(Mpow(M,n-1),R);
        fout<<R.m[1][0];
    }
    return 0;
}