imprimeMinusculasMaiusculas.c

void imprimeMinusculasMaiusculas(char* cad)
{// caso base
  if (cad[0] == '\0')
    return;
  
  // passo indutivo
  if (cad[0] >= 'a' && cad[0] <= 'z')
    // transforma de minuscula pra maiuscula
    cad[0] = cad[0] - ('a'-'A');
  else if  (cad[0] >= 'A' && cad[0] <= 'Z')
    // transforma de maiuscula pra minuscula
    cad[0] = cad[0] + ('a'- 'A');
    
  printf("%c", cad[0]);
  return imprimeMinusculasMaiusculas(&(cad[1]));
}