You're missing a closing parenthesis on an if statement.
The problem with the brace formatting you're using is that opening curly braces make it a bit more difficult to see where opening and closing curly braces and parenthesis match up.
void enqueue(int val) {
if (isFull() { <-------------------
cout << "Queue Full!";
}
else if (isEmpty()){
IMHO, this is better:
void enqueue(int val)
{
if (isFull() <---- missing closing parenthesis
{
cout << "Queue Full!";
}
else if (isEmpty())
{