2581 - 소수

	#include <iostream>
	using namespace std;
	int main(void)
	{
	ios_base::sync_with_stdio(false);
	cin.tie(nullptr);
	int num1, num2, minNum, repeat = 1;
	cin >> num1;
	cin >> num2;
	if(num2 == 1) {
	cout << -1 << '\n';
	return 0;
	}
	int primeSum = 0;
	for (int i = num1; i <= num2; i++) {
	if(i < 2) {
	continue;
	}
	int j;
	bool isPrime = true;
	for (j = 2; j * j <= i; j++) {
	if (i % j == 0) {
	isPrime = false;
	break;
	}
	}
	if(isPrime == true) {
	if(repeat == 1) {
	minNum = i;
	--repeat;
	}
	primeSum += i;
	}
	}
	if (primeSum == 0) {
	cout << -1 << '\n';
	} else {
	cout << primeSum << '\n'
	<< minNum << '\n';
	}
	return 0;
	}

view raw 2581.cpp hosted with ❤ by GitHub

문제 :

https://www.acmicpc.net/problem/2581