Cod sursa(job #1706830)

Utilizator mihai9xxMihai9 mihai9xx Data 23 mai 2016 14:58:05
Problema Fractii Scor 100
Compilator cpp Status done
Runda Arhiva de probleme Marime 0.29 kb
Raporteaza aceasta sursa 
#include <fstream>
using namespace std;
int s[1000001],n,i,j;
unsigned long long r;
ifstream f("fractii.in");
ofstream g("fractii.out");
int main(){
f>>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;
g<<r+1;
}