Cod sursa(job #2431526)

Utilizator blotucosmincosmin blotucosmin Data 19 iunie 2019 21:11:02
Problema Fractii Scor 30
Compilator cpp-64 Status done
Runda Arhiva de probleme Marime 0.35 kb
Raporteaza aceasta sursa 
#include<bits/stdc++.h>
using namespace std;
ifstream fin("fractii.in");
ofstream fout("fractii.out");
int v[1000001],i,j,n,s;
int main()
{
    fin>>n;
    for(i=1;i<=n;++i)
        v[i]=i-1;
    for(i=2;i<=n;++i)
     for(j=i+i;j<=n;j+=i)
        v[j]=v[j]-v[i];
     for(i=1;i<=n;++i)
        s+=v[i];
     fout<<2*s+1;
    return 0;
}