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

Yes

The meaning, spelling, and grammar of "encontrou" are identical in both Brazilian and Continental Portuguese. The only difference is in pronunciation. In Brazilian Portuguese, the vowels are typically more open and clearly articulated. In Continental Portuguese, unstressed vowels (such as the "e" in the prefix "en-") are often reduced, shortened, or "swallowed," which gives the dialect a more consonant-heavy sound.

Brazilian Portuguese Examples

1. Ele encontrou a chave no chão. (He found the key on the floor.)
2. Ela encontrou o namorado no shopping. (She met her boyfriend at the mall.)
3. O cachorro encontrou um osso. (The dog found a bone.)
4. O professor encontrou um erro no trabalho. (The professor found an error in the work.)
5. A criança encontrou um brinquedo perdido. (The child found a lost toy.)

Continental Portuguese Examples

1. Ele encontrou a chave no chão. (He found the key on the floor.)
2. Ela encontrou o namorado no centro comercial. (She met her boyfriend at the shopping center.)
3. O cão encontrou um osso. (The dog found a bone.)
4. O professor encontrou um erro no trabalho. (The professor found an error in the work.)
5. O miúdo encontrou um brinquedo perdido. (The kid found a lost toy.)