Submission

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Score: 0

User: Ecir

Problemset: จำนวนเฉพาะก่อนหน้า

Language: cpp

Time: 0.013 second

Submitted On: 2025-01-14 09:11:46

#include <bits/stdc++.h>
using namespace std;
vector<int> prime;
bitset<10000000> p;
int main(){
	ios::sync_with_stdio(0);cin.tie(0);
	for(int i=2;i<=10000000;i++){
		if(p[i]==0){
			prime.push_back(i);
			for(int j=2;i*j<=10000000;j++)p[i*j]=1;
		}
	}
//	for(auto e:prime) cout << e << " ";
	int n;cin >> n;
	int pos=lower_bound(prime.begin(),prime.end(),n)-prime.begin();
//	cout << pos ;
	if(pos<5) {
		for(int i=0;i<pos;i++){
			cout << prime[i] << " ";
		}
	}
	else {
		for(int i=pos-5;i<pos;i++){
			cout << prime[i] << " ";
		}
	}
	return 0;
}