How to set list's offsets correctly about orc HOT 3 CLOSED

ORC_UNIQUE_PTR<OutputStream> outStream = writeLocalFile("test-file.orc");
ORC_UNIQUE_PTR<Type> schema(
    Type::buildTypeFromString("struct<id:int,list1:array<string>>"));
WriterOptions options;
ORC_UNIQUE_PTR<Writer> writer = createWriter(*schema, outStream.get(), options);

std::unique_ptr<Writer> writer = createWriter(*type, stream.get(), options);

uint64_t batch_size = 1024, row_count = 2048;

std::unique_ptr<ColumnVectorBatch> batch =
    writer->createRowBatch(row_count);
StructVectorBatch &root_batch =
    dynamic_cast<StructVectorBatch &>(*batch.get());
LongVectorBatch &id_batch =
    dynamic_cast<LongVectorBatch &>(*struct_batch.fields[0]);
ListVectorBatch &list_batch =
    dynamic_cast<ListVectorBatch &>(*struct_batch.fields[1]);
StringVectorBatch &str_batch =
    dynamic_cast<StringVectorBatch &>(*list_batch.elements.get());

std::vector<std::string> vs{"str1", "str2"};

char **data         = str_batch.data.data();
int64_t *offsets    = list_batch.offsets.data();
uint64_t offset     = 0, rows = 0;
for (size_t i = 0; i < row_count; ++i) {
    offsets[rows] = static_cast<int64_t>(offset);

    id_batch.data[rows] = articles[i]->get_id();

    for (auto &s : vs)
    {
        data[offset] = &s[0];
        str_batch.length[offset++] = s.size();
    }

    rows++;
    if (rows == batch_size) 
    {
        offsets[rows] = offset; // new line
        root_batch.numElements = rows;
        id_batch.numElements   = rows;
        list_batch.numElements = rows;

        writer->add(*batch);
        rows = 0;
        offset = 0;
    }
}

if (rows != 0) 
{
    offsets[rows] = offset; // new line
    root_batch.numElements = rows;
    id_batch.numElements   = rows;
    list_batch.numElements = rows;

    writer->add(*batch);
    rows = 0;
    offset = 0;
}

writer->close();