Cod sursa(job #2933515)
Utilizator | Data | 5 noiembrie 2022 11:21:54 | |
---|---|---|---|
Problema | Fractii | Scor | 100 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva de probleme | Marime | 0.47 kb |
#include <bits/stdc++.h>
using namespace std;
ifstream f("fractii.in");
ofstream g("fractii.out");
long long i,j,n,e[1000002];
int main()
{
f>>n;
for(i=1;i<=1000000;i++)
e[i]=i;
for(i=2;i<=1000000;i++)
{
if(e[i]==i)
{
for(j=i;j<=1000000;j=j+i)
{
e[j]=e[j]/i*(i-1);
}
}
}
for(i=2;i<=1000000;i++)
e[i]=e[i]+e[i-1];
g<<2*e[n]-1;
return 0;
}