Ответ:
int main()
{
cin >> number;
if (number >= 1 && number <= 6) {</p>
cout << "Ночь"</p>
}
else if (number >= 7 && number <= 12) {</p>
cout << "Утро"</p>
}
else if (number >= 13 && number <= 18) {</p>
cout << "День"</p>
}
else if (number >= 18 && number <= 24) {</p>
cout << "Вечер"</p>
}
return 0;
}