单选题库

int x = 3;
void f(int& x){
    x += 2;
}
int main(){
    int x = 10;
    f(x);
    cout << x << " " << ::x;
}

void fun(int a, int &b, int *c){
    a += 1;
    b += 2;
    *c += 3;
}

int main(){
    int x = 1, y = 1, z = 1;
    fun(x, y, &z);
    cout << x << " " << y << " " << z;
}

int a[3][4] = {
    {1,2,3,4},
    {5,6,7,8},
    {9,10,11,12}
};
int (*p)[4] = a;

int main() {
    int a = 5;
    int* p = &a;
    int** q = &p;
    **q += 7;
    cout << a << " " << *p;
}

int f(int x = 2){
    return x * 3;
}

int main(){
    cout << f() << " " << f(4);
}