Is the word longa the same in Brazilian and European Portuguese?

Yes

The only differences between Brazilian and Continental Portuguese regarding this word are phonetic. In Brazilian Portuguese, vowels tend to be more "open" and clearly articulated, making the "a" at the end of "longa" quite audible. In Continental Portuguese, unstressed vowels are often "reduced" or "closed," meaning the final "a" is much shorter, softer, and sometimes almost swallowed in natural speech.

Brazilian Portuguese Examples

1. A viagem de ônibus foi muito longa. (The bus trip was very long.)
2. Ela tem uma longa trajetória na empresa. (She has a long career at the company.)
3. A espera pelo médico foi longa. (The wait for the doctor was long.)
4. Essa é uma longa lista de tarefas. (That is a long list of tasks.)
5. A lista de compras está ficando muito longa. (The shopping list is getting very long.)

Continental Portuguese Examples

1. A viagem de autocarro foi muito longa. (The bus trip was very long.)
2. Ela tem uma longa trajetória na empresa. (She has a long career at the company.)
3. A espera pelo médico foi longa. (The wait for the doctor was long.)
4. Esta é uma longa lista de tarefas. (This is a long list of tasks.)
5. A lista de compras está a ficar muito longa. (The shopping list is getting very long.)