Cod sursa(job #3204651)

Utilizator Ilinca_Radu_2022Radu Ilinca-Rucsandra Ilinca_Radu_2022 Data 17 februarie 2024 11:16:56
Problema Fractii Scor 30
Compilator cpp-64 Status done
Runda Arhiva de probleme Marime 0.93 kb
#include <bits/stdc++.h>
#define NRMARE 1000000
using namespace std;
ifstream fin("fractii.in");
ofstream fout("fractii.out");
bool c[NRMARE+5];
int v[NRMARE/10+5], s, i, j, q, n;
int fi(int x) {
    if (c[x]==0) return x-1;
    if (x==1) return 1;
    int nr, rez=1, d=1;
    while (v[d]*v[d]<=x) {
        nr=1;
        while (x%v[d]==0) {
            nr*=v[d];
            x/=v[d];
        }
        if (nr>1) rez*=(nr-nr/v[d]);
        d++;
    }
    if (x>1) rez*=(x-1);
    return rez;
}
void ciur() {
    c[0]=c[1]=1;
    for (i=2; i<=n; i++) {
        if (c[i]==1) continue;
        for (j=2; j<=n/i; j++) {
            c[i*j]=1;
        }
    }
    for (i=2; i<=n; i++) if (c[i]==0) v[++q]=i;
    for (i=1; i<=q; i++) cout<<v[i]<<' ';
    cout<<'\n';
}
int main()
{
    fin>>n;
    ciur();
    for (i=1; i<=n; i++) {
        s+=fi(i);
    }
    cout<<fi(10);
    s=s*2-1;
    fout<<s;
    return 0;
}