Cod sursa(job #1577213)

Utilizator Mihai9Oniga Mihai Mihai9 Data 23 ianuarie 2016 12:25:11
Problema Fractii Scor 90
Compilator cpp Status done
Runda Arhiva de probleme Marime 0.25 kb
Raporteaza aceasta sursa 
#include <fstream>
using namespace std;unsigned long long s[1000001],n,i,j,r;ifstream fin("fractii.in");ofstream fout("fractii.out");int main(){fin>>n;for(i=2;i<=n;i++){s[i]=i-1;}for(i=2;i<=n;i++){r+=s[i];for(j=i+i;j<=n;j=j+i){s[j]-=s[i];}}r*=2;fout<<r+1;}