Cod sursa(job #2779584)
Utilizator | Data | 4 octombrie 2021 11:46:29 | |
---|---|---|---|
Problema | Fractii | Scor | 0 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva de probleme | Marime | 0.42 kb |
#include <fstream>
#define NMAX 1000000
using namespace std;
ifstream cin ("fractii.in");
ofstream cout ("fractii.out");
int f[NMAX + 1];
int main() {
int n, i, j;
long long sol;
cin >> n;
sol = 1;
for (i = 2; i <= n; i++) {
sol += (i - 1 - f[i]) * 2;
if (f[i] == 0) {
for (j = 2 * i; j <= n; j += i)
f[j] += ((j / i) - 1);
}
}
cout << sol;
return 0;
}