C++ :

#include <iostream>
using namespace std;
int main() {
    char ch;
    cin >> ch;
    char lowerCh = (ch >= 'A' && ch <= 'Z') ? (ch + 32) : ch;
    if ((lowerCh >= 'a' && lowerCh <= 'z') &&
        lowerCh != 'a' && lowerCh != 'e' && lowerCh != 'i' && lowerCh != 'o' && lowerCh != 'u') {
        cout << "是辅音字母" << endl;
    } else {
        cout << "不是辅音字母" << endl;
    }
    return 0;
}