Cod sursa(job #2863644)

Utilizator razvan.chChelariu Razvan Dumitru razvan.ch Data 7 martie 2022 00:48:10
Problema Al k-lea termen Fibonacci Scor 0
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.02 kb
#include<bits/stdc++.h>
#define ll long long
#define mod 666013

using namespace std;

void multiply(int F[2][2], int M[2][2]);
void power(int F[2][2], int n);
int fib(int n)
{
    int F[2][2] = {{1, 1}, {1, 0}};
    if (n == 0)
        return 0;
    power(F, n - 1);

    return F[0][0]%mod;
}


void power(int F[2][2], int n)
{
    if(n == 0 || n == 1)
       return;
    int M[2][2] = {{1, 1}, {1, 0}};

    power(F, n / 2);
    multiply(F, F);

    if (n % 2 != 0)
        multiply(F, M);
}

void multiply(int F[2][2], int M[2][2])
{
    int x = F[0][0] * M[0][0] + F[0][1] * M[1][0];
    int y = F[0][0] * M[0][1] + F[0][1] * M[1][1];
    int z = F[1][0] * M[0][0] + F[1][1] * M[1][0];
    int w = F[1][0] * M[0][1] + F[1][1] * M[1][1];

    F[0][0] = x;
    F[0][1] = y;
    F[1][0] = z;
    F[1][1] = w;
}

int main()
{
    FILE *in = fopen("kfib.in","r");
    FILE *out = fopen("kfib.out","w");

    ll n;

    fscanf(in,"%lld",&n);
    n=fib(n)%mod;
    fprintf(out,"%lld",n);
}