2581: 소수 / C++

문제

 

풀이

#include <iostream>

using namespace std;

bool isPrime(int n) {
	if (n == 1) return false;

	for (int i = 2; i * i <= n; i++)
		if (n % i == 0) return false;

	return true;
}

int main() {
	int n, m;
	int result = 0, min = 0;

	cin >> m >> n;

	for (int i = m; i <= n; i++) {
		if (isPrime(i)) {
			result += i;
			if (min == 0) min = i;
		}
	}

	if (result == 0) cout << "-1";
	else cout << result << "\n" << min;

	return 0;
}