Cod sursa(job #1439488)

Utilizator sanduclaudia95sandu iuliana claudia sanduclaudia95 Data 22 mai 2015 14:15:55
Problema Fractii Scor 100
Compilator cpp Status done
Runda Arhiva de probleme Marime 0.31 kb
Raporteaza aceasta sursa 
#include <fstream>
#define dim 1000005
using namespace std;ifstream fin("fractii.in");ofstream fout("fractii.out");int n,i,f[dim],j;long long s;int main(){fin>>n;for(i=2;i<=n;i++){f[i]=i;}for(i=2;i<=n;i++){if(f[i]==i){for(j=i;j<=n;j+=i){f[j]=f[j]/i*(i-1);}}}for(i=1;i<=n;i++){s+=(f[i]*2);}fout<<s+1<<"\n";return 0;}