c++ 乘法表.1

iostream ctime vector tring using namespace std; int main() {     srand(time(NULL));     int random = rand() % 4;     vector v{"12 X 7 = ", "12 X 8 = ", "12 X 9 = ", "12 X 11 = "};     int answer;     while(1)     {         switch(random)         {             case 1: cout << v[0]; cin >> answer; if( answer == 84) cout << "Correct!\n"; else cout << "Worng.";             case 2: cout << v[1]; cin >> answer; if( answer == 96) cout << "Correct!\n"; else cout << "Worng.";             case 3: cout << v[2]; cin >> answer; if( answer == 108) cout << "Correct!\n"; else cout << "Worng.";             case 4: cout << v[3]; cin >> answer; if( answer == 132) cout << "Correct!\n"; else cout << "Worng.";         }     }; }