Java Float to Long Typecast

Here

return (long) x/y; 

You are casting x as long but the entire expression is still float because of y and hence when you try to return it , it shows error. It is same as return ((long)x/y);

Better :

return (long) (x/y);

The only issue here is how things are parenthesized. You'd be fine if you wrote

return (long) (x / y);

When you wrote (long) x / y, that was treated as ((long) x) / y, which is a float according to the typing rules of Java.