test/library_checker/number_theory/enumerate_primes.test.cpp

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• Last update: 2024-11-13 13:43:26+09:00
• Problem: https://judge.yosupo.jp/problem/enumerate_primes

Depends on

• Prime Sieve (エラトステネスの篩) (lib/math/prime_sieve.hpp)

Code

#define PROBLEM "https://judge.yosupo.jp/problem/enumerate_primes"
#include <bits/stdc++.h>
using namespace std;

#include "../../../lib/math/prime_sieve.hpp"

int main(){
    int n, a, b; cin >> n >> a >> b;
    PrimeSieve<int> s(n);
    int cnt = s.getPrimeCount();
    vector<int> res;
    for(int i = b; i < cnt; i += a){
        res.push_back(s.getKthPrime(i));
    }
    int cnt2 = res.size();
    cout << cnt << " " << cnt2 << "\n";
    for(int i = 0; i < cnt2; i++){
        if(i >= 1) cout << " ";
        cout << res[i];
    }
    cout << "\n";
}

#line 1 "test/library_checker/number_theory/enumerate_primes.test.cpp"
#define PROBLEM "https://judge.yosupo.jp/problem/enumerate_primes"
#include <bits/stdc++.h>
using namespace std;

#line 2 "lib/math/prime_sieve.hpp"

/**
 * @brief Prime Sieve (エラトステネスの篩)
 * @docs docs/math/prime-sieve.md
 */

#line 9 "lib/math/prime_sieve.hpp"

template <typename T>
struct PrimeSieve{
    int n, half;
    std::vector<bool> sieve;
    std::vector<T> prime_list;
    // sieve[i] ... 2 * i + 1

    PrimeSieve(T _n) : n(_n){
        init();
    }

    void init(){
        if(n < 2){
            return;
        }
        half = (n + 1) / 2;
        sieve.assign(half, true);
        sieve[0] = false;
        prime_list.emplace_back(2);
        for(long long i = 1; 2 * i + 1 <= n; ++i){
            if(!sieve[i]) continue;
            T p = 2 * i + 1;
            prime_list.emplace_back(p);
            for(long long j = 2 * i * (i + 1); j < half; j += p){
                sieve[j] = false;
            }
        }
    }

    bool isPrime(T x){
        if(x == 2) return true;
        if(x % 2 == 0) return false;
        return sieve[x / 2];
    }

    T getPrimeCount(){
        return prime_list.size();
    }

    T getKthPrime(int k){
        return prime_list[k];
    }
};
#line 6 "test/library_checker/number_theory/enumerate_primes.test.cpp"

int main(){
    int n, a, b; cin >> n >> a >> b;
    PrimeSieve<int> s(n);
    int cnt = s.getPrimeCount();
    vector<int> res;
    for(int i = b; i < cnt; i += a){
        res.push_back(s.getKthPrime(i));
    }
    int cnt2 = res.size();
    cout << cnt << " " << cnt2 << "\n";
    for(int i = 0; i < cnt2; i++){
        if(i >= 1) cout << " ";
        cout << res[i];
    }
    cout << "\n";
}

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