DSA06014 - Tổng cặp số nguyên tố

#include<bits/stdc++.h>
using namespace std;

long long prime[10000001];
vector<int> snt;

void sangEratosthenes(){
	//Gan tat ca mang ban dau deu la so nguyen to;
	for(int i = 0; i < 1000000; i++){
		prime[i] = 1;
	}
	//So 0 va so 1 luôn khong phai la so nguyen to nen gan cho chung bang 0;
	prime[0] = prime[1] = 0;
	//Duyet tu i den sqrt(1000000) vi cac so mu 2 se luon co it nhat 3 uoc
	for(int i=2; i < sqrt(1000000); i++){
		if(prime[i]){
			snt.push_back(i);
			for(int j = i*i; j <= 1000000; j+=i){
				prime[j] = 0;
			}
		}
	}
//	for(int i = 0; i < snt.size(); i++){
//		cout<<snt[i]<<" ";
//	}
}

int main(){
	sangEratosthenes();
	int t;
	cin>>t;
	while(t--){
		int n;
		cin>>n;
		bool check = false;
		for(int i = 0; i < snt.size(); i++){
			if(!check){
				for(int j = 0; j < snt.size(); j++){
					if(snt[i] + snt[j] == n){
						check = true;
						cout<<snt[i]<<" "<<snt[j]<<endl;
					}
				}
			}
			
		}
		if(!check){
			cout<<"-1"<<endl;
		}
	}
	return 0;
}