import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;

public class ScoreCalculator {
    public static void main(String[] args) {
        String filePath = "scores.txt";
        int sum = 0;
        int count = 0;

        // try-with-resources 自动关闭流，无需手动 close()
        try (BufferedReader br = new BufferedReader(new FileReader(filePath))) {
            String line;
            while ((line = br.readLine()) != null) {
                try {
                    // 处理数字格式错误
                    int score = Integer.parseInt(line.trim());
                    sum += score;
                    count++;
                } catch (NumberFormatException e) {
                    System.err.println("警告：无法解析分数 '" + line + "'，跳过该数据。");
                }
            }

            if (count > 0) {
                double average = (double) sum / count;
                System.out.printf("平均分：%.2f%n", average);
            } else {
                System.out.println("文件中没有有效分数数据。");
            }

        } catch (java.io.FileNotFoundException e) {
            System.err.println("错误：文件不存在，请检查路径 '" + filePath + "'。");
        } catch (IOException e) {
            System.err.println("错误：读取文件失败 - " + e.getMessage());
        }
    }
}