Cod sursa(job #2871864)

Utilizator BlueLuca888Girbovan Robert Luca BlueLuca888 Data 15 martie 2022 20:58:51
Problema Mins Scor 0
Compilator cpp-64 Status done
Runda Arhiva de probleme Marime 0.81 kb
#include <bits/stdc++.h>
#pragma GCC optimize ("Ofast")

using namespace std;

ifstream fin  ("mins.in");
ofstream fout ("mins.out");

const int LIMIT = 1e6;
bitset <LIMIT + 5> ciur;
int phi[LIMIT + 5];
void update(int x){
    for(int i=2*x; i<=LIMIT; i+=i){
        ciur[i] = true;
        phi[i] -= phi[i] / x;
    }
}

int c, d;
long long sol;

signed main (){
    ios_base::sync_with_stdio(false);
    fin.tie(nullptr);
    fout.tie(nullptr);

    for(int i=1; i<=LIMIT; i++)
        phi[i] = i;

    ciur[0] = ciur[1] = true;
    update(2);
    update(3);
    for(int i=5; i<=LIMIT; i+=6){
        if(!ciur[ i ]) update( i );
        if(!ciur[i+2]) update(i+2);
    }

    fin>>c>>d;

    for(int i=1; i < max(c, d); i++)
        sol += phi[i];

    fout<<sol - 1;
    return 0;
}