C++,求[ n,m ]之间的素数

int main(){
	int m, n;
	cin >> n >> m;
	for (int i = n; i <= m; i++) {
		int a = 1;
		for (int j = 2; j * j <= i; j++) {
			if (i % j == 0) {
				a = 0;
				break;
			}
		}
		if (a == 1) {
			cout << i << endl;
		}
	}
}