为什么无法输出任何内容 哭了~~

#include <iostream>
using namespace std;

 void outa ()
{
    cout<<"XXX";
    cout<<"X.X";
    cout<<"X.X";
    cout<<"X.X";
    cout<<"XXX";
}
 void b ()
{
    cout<<"...";
    cout<<"...";
    cout<<"...";
    cout<<"...";
    cout<<"...";
}
void c ()
{
    cout<<"XXX";
    cout<<"..X";
    cout<<"X.X";
    cout<<"X..";
    cout<<"XXX";
}
void d ()
{
    cout<<"XXX";
    cout<<"..X";
    cout<<"X.X";
    cout<<"..X";
    cout<<"XXX";
}
void e ()
{
    cout<<"X.X";
    cout<<"X.X";
    cout<<"XXX";
    cout<<"..X";
    cout<<"..X";
}
void f ()
{
    cout<<"XXX";
    cout<<"X..";
    cout<<"X.X";
    cout<<"..X";
    cout<<"XXX";
}
void g ()
{
    cout<<"XXX";
    cout<<"X..";
    cout<<"XXX";
    cout<<"X.X";
    cout<<"XXX";
}
void h ()
{
    cout<<"XXX";
    cout<<"..X";
    cout<<"..X";
    cout<<"..X";
    cout<<"..X";
}
void i ()
{
    cout<<"XXX";
    cout<<"X.X";
    cout<<"XXX";
    cout<<"X.X";
    cout<<"XXX";
}
void j ()
{
    cout<<"XXX";
    cout<<"X.X";
    cout<<"XXX";
    cout<<"..X";
    cout<<"XXX";
}

int main ()
{
    int n;
    cin>>n;

    int a[n];

    for(int i = 0; i < n;i++){
        cin>>a[i];
    }

    for(int i = 0; i < n ; i++){
        if(a[i] == 0){
            outa;
        }
        if(a[i] == 1){
            b;
        }
        if(a[i] == 2){
            c;
        }
        if(a[i] == 3){
            d;
        }
        if(a[i] == 4){
            e;
        }
        if(a[i] == 5){
            f;
        }
        if(a[i] == 6){
            g;
        }
        if(a[i] == 7){
            h;
        }
        if(a[i] == 8){
            i;
        }
        if(a[i] == 9){
            j;
        }
    }
    return 0;
}
```cpp