sqf

README.md

@@ -1,2 +0,0 @@
-# mathStudyAPP
-

data/sqf/2025-10-02-11-29-36.txt

@@ -0,0 +1,20 @@
+1. 37 + 35
+
+2. 82 * 28
+
+3. (16 / 56) + 42
+
+4. 6 * 52 + 35
+
+5. (99 + 26) + 37
+
+6. 40 * 63
+
+7. 52 - 61 - 16 - 70 * 51
+
+8. 65 + 83
+
+9. 84 / 64
+
+10. 24 - 47 + 21 + 1 - 33
+

data/users.cfg

@@ -0,0 +1,10 @@
+王五3	123	HIGH	wangwu3@example.com
+王五2	123	HIGH	wangwu2@example.com
+王五1	123	HIGH	wangwu1@example.com
+张三3	123	PRIMARY	zhangsan3@example.com
+张三1	123	PRIMARY	zhangsan1@example.com
+张三2	123	PRIMARY	zhangsan2@example.com
+李四3	123	MIDDLE	lishi3@example.com
+sqf	Aa123456	PRIMARY	sqf090815@hnu.edu.cn
+李四1	123	MIDDLE	lishi1@example.com
+李四2	123	MIDDLE	lishi2@example.com

doc/README.md

@@ -0,0 +1,27 @@
+# mathStudyAPP
+## 📂 项目结构
+src/
+├─ Main.java
+├─ controller/
+│   ├─ AssignController.java
+│   └─ FunctionController.java
+├─ model/
+│   ├─ Login.java
+│   ├─ LanguageSwitch.java
+│   ├─ QuestionGenerator.java
+│   ├─ Generator.java
+│   ├─ LoadFile.java
+│   ├─ Save.java
+│   ├─ Create.java
+│   └─ Paper.java
+└─ view/
+    ├─ LoginFrame.java
+    ├─ RegisterFrame.java
+    ├─ MainMenuFrame.java
+    ├─ ExamSetupFrame.java
+    ├─ ExamFrame.java
+    └─ ResultFrame.java
+
+---
+
+

mathStudyApp.iml

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+<?xml version="1.0" encoding="UTF-8"?>
+<module type="JAVA_MODULE" version="4">
+  <component name="NewModuleRootManager" inherit-compiler-output="true">
+    <exclude-output />
+    <content url="file://$MODULE_DIR$">
+      <sourceFolder url="file://$MODULE_DIR$/src" isTestSource="false" />
+    </content>
+    <orderEntry type="inheritedJdk" />
+    <orderEntry type="sourceFolder" forTests="false" />
+    <orderEntry type="library" name="lib" level="project" />
+    <orderEntry type="library" name="jakarta.activation-2.0.1 (2)" level="project" />
+    <orderEntry type="library" name="jakarta.mail-2.0.1 (2)" level="project" />
+  </component>
+</module>

src/Main.java

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+import javax.swing.SwingUtilities;
+import view.LoginFrame;
+
+/**
+ * 程序入口
+ */
+public class Main {
+
+  public static void main(String[] args) {
+    SwingUtilities.invokeLater(() -> new LoginFrame());
+  }
+}

src/controller/AssignController.java

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+package controller;
+
+import model.Login;
+import model.LanguageSwitch;
+import view.ExamSetupFrame;
+
+import javax.swing.JOptionPane;
+
+/**
+ * 登录后流程控制：负责从登录跳转到出题设置
+ */
+public class AssignController {
+  public void loginSuccess(Login.Account user) {
+    JOptionPane.showMessageDialog(null,
+        "登录成功。当前选择为 " + LanguageSwitch.levelToChinese(user.level) + " 出题");
+    new ExamSetupFrame(user);
+  }
+}

src/controller/FunctionController.java

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+package controller;
+
+import model.Create;
+import model.Login;
+import model.Paper;
+import view.ExamFrame;
+
+import javax.swing.JOptionPane;
+
+/**
+ * 题目生成控制器：接收题数与用户信息，调用 Create 生成 Paper 并打开 ExamFrame
+ */
+public class FunctionController {
+  private Login.Account user;
+
+  public FunctionController(Login.Account user) {
+    this.user = user;
+  }
+
+  public void startExam(int n) {
+    if (n < 10 || n > 30) {
+      JOptionPane.showMessageDialog(null, "题目数量的有效输入范围是 10-30");
+      return;
+    }
+    Paper paper = Create.create(n, user.level, user);
+    if (paper == null || paper.size() == 0) {
+      JOptionPane.showMessageDialog(null, "未能生成题目（可能因去重约束导致）。");
+      return;
+    }
+    JOptionPane.showMessageDialog(null, "已生成 " + paper.size() + " 道题，开始答题。");
+    new ExamFrame(paper, user);
+  }
+}

src/model/Create.java

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+package model;
+
+import java.util.*;
+import javax.script.*;
+
+/**
+ * 负责生成试卷并创建选择题选项（四选一）
+ */
+public class Create {
+
+  // 把数学表达式转换为 JS 可执行表达式的简单转换器
+  private static String toJsExpr(String expr) {
+    String s = expr;
+    s = s.replaceAll("\\^2", ".pow2"); // 临时占位
+    s = s.replaceAll("sqrt\\(", "Math.sqrt(");
+    s = s.replaceAll("sin\\(", "Math.sin(Math.toRadians(");
+    s = s.replaceAll("cos\\(", "Math.cos(Math.toRadians(");
+    s = s.replaceAll("tan\\(", "Math.tan(Math.toRadians(");
+    // 修复 sin(Math.toRadians(x) 末尾多一层 ) -> we need to close paren
+    // Simple approach: for each "Math.sin(Math.toRadians(", there will be following number or parenthesis, we close later with "))"
+    // Replace our .pow2 placeholder into Math.pow(x,2)
+    // Handle pow2: we earlier converted x^2 -> x.pow2, so replace (\d+|...) .pow2 to Math.pow(that,2)
+    // For simplicity, replace pattern "([0-9)]+)\\.pow2" with "Math.pow($1,2)" — approximate
+    s = s.replaceAll("(\\d+)\\.pow2", "Math.pow($1,2)");
+    // If there are parentheses before .pow2: ") .pow2" unlikely; accept some limitations.
+    // For sin/cos/tan we changed 'sin(' -> 'Math.sin(Math.toRadians(' so must add two closing ) after the argument.
+    // To keep it simple, replace "Math.sin(Math.toRadians(" -> "Math.sin(Math.toRadians(" and later we will ensure parentheses in evaluation by appending "))" when needed.
+    // We'll also replace any leftover "^2" directly
+    s = s.replaceAll("\\^2", "");
+    // Finally, replace any multiple spaces
+    s = s.replaceAll("\\s+", "");
+    return s;
+  }
+
+  // 评估表达式数值（double），若失败抛异常
+  // 评估表达式数值（double），若失败抛异常
+  private static double evalExpression(String expr) throws ScriptException {
+    return ExpressionEvaluator.evaluate(expr);
+  }
+
+
+  /**
+   * 生成试卷：返回 Paper 对象（questions, options, correctIndex）
+   */
+  public static Paper create(int n, Login.Level currentLevel, Login.Account user) {
+    List<String> existing = LoadFile.loadExistingQuestions(user.username);
+    Generator qg = new Generator(currentLevel, existing);
+    List<String> paper = qg.generatePaper(n);
+    if (paper.isEmpty()) {
+      return null;
+    }
+
+    // 为每道题生成 4 个选项：一个正确值（三位有效数）加上 3 个干扰项
+    List<String[]> optionsList = new ArrayList<>();
+    int[] correctIdx = new int[paper.size()];
+    for (int i = 0; i < paper.size(); i++) {
+      String q = paper.get(i);
+      double correctVal;
+      try {
+        correctVal = evalExpression(q);
+      } catch (Exception ex) {
+        // 如果无法精确计算（如复杂表达式），我们退而使用字符串匹配：将题目文本作为正确选项，生成三个变体文本
+        String[] opts = new String[4];
+        opts[0] = q;
+        opts[1] = q + " + 1";
+        opts[2] = q + " - 1";
+        opts[3] = "错误：" + q;
+        shuffleArray(opts);
+        int idx = findIndex(opts, q);
+        optionsList.add(opts);
+        correctIdx[i] = idx;
+        continue;
+      }
+
+      // 格式化正确值为保留3位小数（若为整数则不显示小数）
+      String correctStr = formatNumber(correctVal);
+
+      // 判断是否为整数答案
+      boolean isIntAnswer = Math.abs(correctVal - Math.round(correctVal)) < 1e-6;
+
+
+// 产生三个干扰值
+      Set<String> optsSet = new LinkedHashSet<>();
+      optsSet.add(correctStr);
+      Random r = new Random();
+      int attempts = 0;
+      while (optsSet.size() < 4 && attempts < 50) {
+        attempts++;
+        double delta;
+        if (isIntAnswer) {
+          // 整数题：干扰项也是整数（偏差 ±1~±10）
+          delta = r.nextInt(10) + 1;
+          if (r.nextBoolean()) delta = -delta;
+        } else {
+          // 小数题：随机偏差比例
+          delta = (Math.abs(correctVal) < 1e-6)
+              ? (r.nextDouble() * 5 + 1)
+              : (r.nextGaussian() * Math.max(1, Math.abs(correctVal) * 0.15));
+        }
+        double cand = correctVal + delta;
+        String s = formatNumber(cand);
+        optsSet.add(s);
+      }
+// 不足 4 个时补齐
+      while (optsSet.size() < 4) {
+        double cand = isIntAnswer
+            ? correctVal + (r.nextInt(10) - 5)
+            : correctVal + (r.nextDouble() * 2 - 1);
+        optsSet.add(formatNumber(cand));
+      }
+
+      String[] optsArr = optsSet.toArray(new String[0]);
+// 随机打乱并记录正确项位置
+      shuffleArray(optsArr);
+      int idx = findIndex(optsArr, correctStr);
+      optionsList.add(optsArr);
+      correctIdx[i] = idx;
+
+    }
+
+    // 保存试卷原文本（题干）到文件（按你的 Save 实现）
+    try {
+      // 为保存，我们保存原题干列表（文本）
+      java.util.List<String> raw = new ArrayList<>();
+      for (String s : paper) raw.add(s);
+      Save.savePaper(user.username, raw);
+    } catch (RuntimeException re) {
+      // 抛给 UI 处理（但仍返回 Paper）
+      System.err.println("保存试卷时出错: " + re.getMessage());
+    }
+
+    return new Paper(paper, optionsList, correctIdx);
+  }
+
+  private static void shuffleArray(String[] arr) {
+    Random r = new Random();
+    for (int i = arr.length - 1; i > 0; i--) {
+      int j = r.nextInt(i + 1);
+      String t = arr[i];
+      arr[i] = arr[j];
+      arr[j] = t;
+    }
+  }
+
+  private static int findIndex(String[] arr, String target) {
+    for (int i = 0; i < arr.length; i++) if (arr[i].equals(target)) return i;
+    return 0;
+  }
+
+  private static String formatNumber(double v) {
+    if (Math.abs(v - Math.round(v)) < 1e-6) {
+      return String.valueOf((long)Math.round(v));
+    } else {
+      return String.format("%.3f", v);
+    }
+  }
+}

src/model/ExpressionEvaluator.java

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+package model;
+import java.util.*;
+
+public class ExpressionEvaluator {
+
+  private static final Map<String, Integer> PRECEDENCE = new HashMap<>();
+  static {
+    PRECEDENCE.put("+", 1);
+    PRECEDENCE.put("-", 1);
+    PRECEDENCE.put("*", 2);
+    PRECEDENCE.put("/", 2);
+    PRECEDENCE.put("^", 3);
+  }
+
+  // 判断是否是运算符
+  private static boolean isOperator(String token) {
+    return PRECEDENCE.containsKey(token);
+  }
+
+  // 运算符优先级
+  private static int precedence(String op) {
+    return PRECEDENCE.get(op);
+  }
+
+  // 将中缀表达式转为逆波兰表达式（RPN）
+  private static List<String> toRPN(String expr) {
+    List<String> output = new ArrayList<>();
+    Stack<String> stack = new Stack<>();
+
+    // 正则拆分 token（数字、函数、符号、括号）
+    StringTokenizer tokenizer = new StringTokenizer(expr, "+-*/^() ", true);
+    while (tokenizer.hasMoreTokens()) {
+      String token = tokenizer.nextToken().trim();
+      if (token.isEmpty()) continue;
+
+      if (token.matches("[0-9.]+")) { // 数字
+        output.add(token);
+      } else if (token.matches("[a-zA-Z]+")) { // 函数
+        stack.push(token);
+      } else if (isOperator(token)) { // 运算符
+        while (!stack.isEmpty() && isOperator(stack.peek())
+            && precedence(stack.peek()) >= precedence(token)) {
+          output.add(stack.pop());
+        }
+        stack.push(token);
+      } else if (token.equals("(")) {
+        stack.push(token);
+      } else if (token.equals(")")) {
+        while (!stack.isEmpty() && !stack.peek().equals("(")) {
+          output.add(stack.pop());
+        }
+        if (!stack.isEmpty() && stack.peek().equals("(")) {
+          stack.pop();
+        }
+        // 如果栈顶是函数，弹出函数
+        if (!stack.isEmpty() && stack.peek().matches("[a-zA-Z]+")) {
+          output.add(stack.pop());
+        }
+      }
+    }
+
+    while (!stack.isEmpty()) {
+      output.add(stack.pop());
+    }
+
+    return output;
+  }
+
+  // 计算逆波兰表达式
+  private static double evalRPN(List<String> rpn) {
+    Stack<Double> stack = new Stack<>();
+    for (String token : rpn) {
+      if (token.matches("[0-9.]+")) {
+        stack.push(Double.parseDouble(token));
+      } else if (isOperator(token)) {
+        double b = stack.pop();
+        double a = stack.pop();
+        switch (token) {
+          case "+": stack.push(a + b); break;
+          case "-": stack.push(a - b); break;
+          case "*": stack.push(a * b); break;
+          case "/": stack.push(a / b); break;
+          case "^": stack.push(Math.pow(a, b)); break;
+        }
+      } else { // 函数
+        double a = stack.pop();
+        switch (token.toLowerCase()) {
+          case "sin": stack.push(Math.sin(Math.toRadians(a))); break;
+          case "cos": stack.push(Math.cos(Math.toRadians(a))); break;
+          case "tan": stack.push(Math.tan(Math.toRadians(a))); break;
+          case "sqrt": stack.push(Math.sqrt(a)); break;
+          default: throw new RuntimeException("未知函数: " + token);
+        }
+      }
+    }
+    return stack.pop();
+  }
+
+  // 对外接口：传入表达式字符串，返回计算结果
+  public static double evaluate(String expr) {
+    List<String> rpn = toRPN(expr);
+    return evalRPN(rpn);
+  }
+
+}

src/model/Generator.java

@@ -0,0 +1,142 @@
+package model;
+
+import java.util.*;
+import java.util.stream.Collectors;
+
+/**
+ * 具体题目生成器
+ */
+public class Generator extends QuestionGenerator {
+
+  public static final Random RAND = new Random();
+  public static final int MAX_ATTEMPTS = 2000;
+
+  public final Login.Level level;
+  public final Set<String> existing;
+
+  public Generator(Login.Level level, List<String> existingQuestions) {
+    this.level = level;
+    this.existing = existingQuestions.stream().map(String::trim).collect(Collectors.toSet());
+  }
+
+  public List<String> generatePaper(int n) {
+    Set<String> generated = new LinkedHashSet<>();
+    int attempts = 0;
+    while (generated.size() < n && attempts < MAX_ATTEMPTS) {
+      attempts++;
+      String q = generateOneQuestion();
+      String key = normalize(q);
+      if (!existing.contains(key) && !generated.contains(key)) {
+        generated.add(q);
+      }
+    }
+    if (generated.size() < n) {
+      System.out.println("注意：无法生成足够的不重复题目，已生成 " + generated.size() + " 道题（请求 " + n + " 道）");
+    }
+    return new ArrayList<>(generated);
+  }
+
+  public String normalize(String s) {
+    return s.replaceAll("\\s+", "").toLowerCase();
+  }
+
+  public String generateOneQuestion() {
+    int operands = RAND.nextInt(5) + 1; // 1..5
+    int operands_p = RAND.nextInt(4) + 2; // 2..5
+    return switch (level) {
+      case PRIMARY -> genPrimary(operands_p);
+      case MIDDLE -> genMiddle(operands);
+      case HIGH -> genHigh(operands);
+    };
+  }
+
+  public String genPrimary(int operands) {
+    if (operands == 1) {
+      return String.valueOf(randInt(1, 100));
+    }
+    List<String> ops = Arrays.asList("+", "-", "*", "/");
+    StringBuilder sb = new StringBuilder();
+    boolean useParens = RAND.nextBoolean();
+    if (useParens && operands >= 3 && RAND.nextBoolean()) {
+      sb.append("(");
+      sb.append(randInt(1, 100)).append(" ").append(randomChoice(ops)).append(" ").append(randInt(1, 100));
+      sb.append(")");
+      for (int i = 2; i < operands; i++) {
+        sb.append(" ").append(randomChoice(ops)).append(" ").append(randInt(1, 100));
+      }
+    } else {
+      sb.append(randInt(1, 100));
+      for (int i = 1; i < operands; i++) {
+        sb.append(" ").append(randomChoice(ops)).append(" ").append(randInt(1, 100));
+      }
+    }
+    return sb.toString();
+  }
+
+  public String genMiddle(int operands) {
+    String expr = genPrimary(operands);
+    if (RAND.nextBoolean()) expr = applySquare(expr);
+    else expr = applySqrt(expr);
+    return expr;
+  }
+
+  public String genHigh(int operands) {
+    String expr = genPrimary(operands);
+    expr = applyTrig(expr);
+    return expr;
+  }
+
+  public String applySquare(String expr) {
+    List<int[]> spans = findNumberSpans(expr);
+    if (spans.isEmpty()) return expr + "^2";
+    int[] s = spans.get(RAND.nextInt(spans.size()));
+    String before = expr.substring(0, s[0]);
+    String num = expr.substring(s[0], s[1]);
+    String after = expr.substring(s[1]);
+    return before + "(" + num + ")^2" + after;
+  }
+
+  public String applySqrt(String expr) {
+    List<int[]> spans = findNumberSpans(expr);
+    if (spans.isEmpty()) return "sqrt(" + expr + ")";
+    int[] s = spans.get(RAND.nextInt(spans.size()));
+    String before = expr.substring(0, s[0]);
+    String num = expr.substring(s[0], s[1]);
+    String after = expr.substring(s[1]);
+    return before + "sqrt(" + num + ")" + after;
+  }
+
+  public String applyTrig(String expr) {
+    List<int[]> spans = findNumberSpans(expr);
+    String func = randomChoice(Arrays.asList("sin", "cos", "tan"));
+    if (spans.isEmpty()) return func + "(" + expr + ")";
+    int[] s = spans.get(RAND.nextInt(spans.size()));
+    String before = expr.substring(0, s[0]);
+    String num = expr.substring(s[0], s[1]);
+    String after = expr.substring(s[1]);
+    return before + func + "(" + num + ")" + after;
+  }
+
+  public List<int[]> findNumberSpans(String expr) {
+    List<int[]> spans = new ArrayList<>();
+    char[] chs = expr.toCharArray();
+    int i = 0, n = chs.length;
+    while (i < n) {
+      if (Character.isDigit(chs[i])) {
+        int j = i;
+        while (j < n && (Character.isDigit(chs[j]))) j++;
+        spans.add(new int[]{i, j});
+        i = j;
+      } else i++;
+    }
+    return spans;
+  }
+
+  public int randInt(int a, int b) {
+    return RAND.nextInt(b - a + 1) + a;
+  }
+
+  public <T> T randomChoice(List<T> list) {
+    return list.get(RAND.nextInt(list.size()));
+  }
+}

src/model/LanguageSwitch.java

@@ -0,0 +1,22 @@
+package model;
+
+public class LanguageSwitch {
+  public static String levelToChinese(Login.Level l) {
+    return switch (l) {
+      case PRIMARY -> "小学";
+      case MIDDLE -> "初中";
+      case HIGH -> "高中";
+      default -> "未知";
+    };
+  }
+
+  public static Login.Level chineseToLevel(String s) {
+    s = s.trim();
+    return switch (s) {
+      case "小学" -> Login.Level.PRIMARY;
+      case "初中" -> Login.Level.MIDDLE;
+      case "高中" -> Login.Level.HIGH;
+      default -> null;
+    };
+  }
+}

src/model/LoadFile.java

@@ -0,0 +1,49 @@
+package model;
+
+import java.nio.charset.StandardCharsets;
+import java.util.*;
+import java.nio.file.*;
+import java.io.IOException;
+import java.nio.file.DirectoryStream;
+import java.util.stream.Collectors;
+
+/**
+ * 读取用户文件夹下已有题目的所有题目文本（用于查重）
+ */
+public class LoadFile {
+
+  public static List<String> loadExistingQuestions(String username) {
+    List<String> all = new ArrayList<>();
+    Path userDir = Paths.get("data", username);
+    if (!Files.exists(userDir)) {
+      return all;
+    }
+    try (DirectoryStream<Path> ds = Files.newDirectoryStream(userDir, "*.txt")) {
+      for (Path p : ds) {
+        List<String> lines = Files.readAllLines(p, StandardCharsets.UTF_8);
+        StringBuilder cur = new StringBuilder();
+        for (String line : lines) {
+          if (line.matches("^\\s*\\d+\\..*")) {
+            if (!cur.isEmpty()) all.add(cur.toString().trim());
+            cur.setLength(0);
+            cur.append(line.replaceFirst("^\\s*\\d+\\.", "").trim());
+          } else {
+            if (line.trim().isEmpty()) {
+              if (!cur.isEmpty()) {
+                all.add(cur.toString().trim());
+                cur.setLength(0);
+              }
+            } else {
+              if (!cur.isEmpty()) cur.append(" ");
+              cur.append(line.trim());
+            }
+          }
+        }
+        if (!cur.isEmpty()) all.add(cur.toString().trim());
+      }
+    } catch (IOException e) {
+      throw new RuntimeException("读取题目文件失败：" + e.getMessage(), e);
+    }
+    return all.stream().map(String::trim).filter(s -> !s.isEmpty()).distinct().collect(Collectors.toList());
+  }
+}

src/model/Login.java

@@ -0,0 +1,160 @@
+package model;
+
+import java.util.Map;
+import java.util.HashMap;
+import java.io.*;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.*;
+
+
+/**
+ * 用户管理（包含预设账户与简单文件持久化）
+ */
+public class Login {
+
+  public enum Level {PRIMARY, MIDDLE, HIGH}
+
+  public static class Account implements Serializable {
+
+    public String username;
+    public String password; // 明文存储（课程项目允许），真实项目请哈希
+    public Level level;
+    public String email;
+
+    public Account(String u, String p, Level l, String email) {
+      this.username = u;
+      this.password = p;
+      this.level = l;
+      this.email = email;
+    }
+  }
+
+  // 内存账户表
+  private static final Map<String, Account> accounts = new HashMap<>();
+  private static final Path USERS_FILE = Paths.get("data", "users.cfg"); // 简单序列化
+
+  static {
+    // 预设账号（与你的个人项目一致）
+    accounts.put("张三1", new Account("张三1", "123", Level.PRIMARY, "zhangsan1@example.com"));
+    accounts.put("张三2", new Account("张三2", "123", Level.PRIMARY, "zhangsan2@example.com"));
+    accounts.put("张三3", new Account("张三3", "123", Level.PRIMARY, "zhangsan3@example.com"));
+
+    accounts.put("李四1", new Account("李四1", "123", Level.MIDDLE, "lishi1@example.com"));
+    accounts.put("李四2", new Account("李四2", "123", Level.MIDDLE, "lishi2@example.com"));
+    accounts.put("李四3", new Account("李四3", "123", Level.MIDDLE, "lishi3@example.com"));
+
+    accounts.put("王五1", new Account("王五1", "123", Level.HIGH, "wangwu1@example.com"));
+    accounts.put("王五2", new Account("王五2", "123", Level.HIGH, "wangwu2@example.com"));
+    accounts.put("王五3", new Account("王五3", "123", Level.HIGH, "wangwu3@example.com"));
+
+    // 加载自文件的额外用户
+    loadFromFile();
+  }
+
+  // 登录验证（GUI 调用）
+  public static Account login(String username, String password) {
+    Account acc = accounts.get(username);
+    if (acc != null && acc.password.equals(password)) {
+      return acc;
+    }
+    return null;
+  }
+
+  // 注册（GUI 调用），若用户名已存在返回 false
+  public static synchronized boolean register(String username, String password, Level level,
+      String email) {
+    if (accounts.containsKey(username)) {
+      return false;
+    }
+    Account acc = new Account(username, password, level, email);
+    accounts.put(username, acc);
+    persistToFile();
+    return true;
+  }
+
+  // 修改密码（需提供原密码），返回是否成功
+  public static synchronized boolean changePassword(String username, String oldPwd, String newPwd) {
+    Account acc = accounts.get(username);
+    if (acc == null) {
+      return false;
+    }
+    if (!acc.password.equals(oldPwd)) {
+      return false;
+    }
+    acc.password = newPwd;
+    persistToFile();
+    return true;
+  }
+
+  // 文件持久化（非常简单的 CSV-like 方案）
+  private static void persistToFile() {
+    try {
+      Path dir = USERS_FILE.getParent();
+      if (dir != null && !Files.exists(dir)) {
+        Files.createDirectories(dir);
+      }
+      try (BufferedWriter bw = Files.newBufferedWriter(USERS_FILE, StandardCharsets.UTF_8)) {
+        for (Account a : accounts.values()) {
+          // 格式: username\tpassword\tlevel\temail
+          bw.write(
+              a.username + "\t" + a.password + "\t" + a.level.name() + "\t" + (a.email == null ? ""
+                  : a.email));
+          bw.newLine();
+        }
+      }
+    } catch (IOException e) {
+      System.err.println("保存用户文件失败: " + e.getMessage());
+    }
+  }
+
+  private static void loadFromFile() {
+    if (!Files.exists(USERS_FILE)) {
+      return;
+    }
+    try {
+      for (String line : Files.readAllLines(USERS_FILE, StandardCharsets.UTF_8)) {
+        if (line.trim().isEmpty()) {
+          continue;
+        }
+        String[] p = line.split("\t");
+        if (p.length >= 3) {
+          String username = p[0], password = p[1];
+          Level level = Level.valueOf(p[2]);
+          String email = p.length >= 4 ? p[3] : "";
+          // 不覆盖预设同名账号（以文件为准覆盖预设）
+          accounts.put(username, new Account(username, password, level, email));
+        }
+      }
+    } catch (IOException e) {
+      System.err.println("读取用户文件失败: " + e.getMessage());
+    } catch (Exception ex) {
+      System.err.println("解析用户文件异常: " + ex.getMessage());
+    }
+  }
+
+  // 验证密码复杂度：6-10 位，必须含大写、小写和数字
+  public static boolean validatePasswordRules(String pwd) {
+    if (pwd == null) {
+      return false;
+    }
+    if (pwd.length() < 6 || pwd.length() > 10) {
+      return false;
+    }
+    boolean hasUpper = false, hasLower = false, hasDigit = false;
+    for (char c : pwd.toCharArray()) {
+      if (Character.isUpperCase(c)) {
+        hasUpper = true;
+      } else if (Character.isLowerCase(c)) {
+        hasLower = true;
+      } else if (Character.isDigit(c)) {
+        hasDigit = true;
+      }
+    }
+    return hasUpper && hasLower && hasDigit;
+  }
+
+  // 供界面显示用户列表（调试）
+  public static Map<String, Account> getAccounts() {
+    return accounts;
+  }
+}

src/model/Paper.java

@@ -0,0 +1,22 @@
+package model;
+
+import java.util.List;
+
+/**
+ * 试卷封装：每一道题为字符串（题干），每题有四个选项（字符串），且标记正确选项索引
+ */
+public class Paper {
+  public final List<String> questions;
+  public final List<String[]> options; // 每题 options[i] 长度为4
+  public final int[] correctIndex; // 每题正确选项下标 0..3
+
+  public Paper(List<String> questions, List<String[]> options, int[] correctIndex) {
+    this.questions = questions;
+    this.options = options;
+    this.correctIndex = correctIndex;
+  }
+
+  public int size() {
+    return questions.size();
+  }
+}

src/model/QuestionGenerator.java

@@ -0,0 +1,33 @@
+package model;
+
+import java.util.List;
+
+public abstract class QuestionGenerator {
+
+  protected QuestionGenerator() {
+  }
+
+  public abstract List<String> generatePaper(int n);
+
+  public abstract String normalize(String s);
+
+  public abstract String generateOneQuestion();
+
+  public abstract String genPrimary(int operands);
+
+  public abstract String genMiddle(int operands);
+
+  public abstract String genHigh(int operands);
+
+  public abstract String applySquare(String expr);
+
+  public abstract String applySqrt(String expr);
+
+  public abstract String applyTrig(String expr);
+
+  public abstract java.util.List<int[]> findNumberSpans(String expr);
+
+  public abstract int randInt(int a, int b);
+
+  public abstract <T> T randomChoice(java.util.List<T> list);
+}

src/model/Save.java

@@ -0,0 +1,32 @@
+package model;
+
+import java.io.BufferedWriter;
+import java.io.IOException;
+import java.nio.file.*;
+import java.text.SimpleDateFormat;
+import java.util.Date;
+import java.util.List;
+import java.nio.charset.StandardCharsets;
+
+public class Save {
+  public static String savePaper(String username, List<String> paper) {
+    Path userDir = Paths.get("data", username);
+    try {
+      if (!Files.exists(userDir)) Files.createDirectories(userDir);
+    } catch (IOException e) {
+      throw new RuntimeException("无法创建用户文件夹：" + e.getMessage(), e);
+    }
+    String timestamp = new SimpleDateFormat("yyyy-MM-dd-HH-mm-ss").format(new Date());
+    Path file = userDir.resolve(timestamp + ".txt");
+    try (BufferedWriter bw = Files.newBufferedWriter(file, StandardCharsets.UTF_8)) {
+      for (int i = 0; i < paper.size(); i++) {
+        bw.write((i + 1) + ". " + paper.get(i));
+        bw.newLine();
+        bw.newLine();
+      }
+    } catch (IOException e) {
+      throw new RuntimeException("保存文件失败：" + e.getMessage(), e);
+    }
+    return file.toString();
+  }
+}

src/view/ExamFrame.java

@@ -0,0 +1,144 @@
+package view;
+
+import javax.swing.*;
+import java.awt.*;
+import model.Paper;
+import model.Login;
+
+/**
+ * 答题界面（选择题，四选一）
+ */
+public class ExamFrame extends JFrame {
+  private Paper paper;
+  private Login.Account user;
+  private int index = 0;
+  private int score = 0;
+
+  private JLabel qLabel;
+  private JRadioButton[] radioBtns = new JRadioButton[4];
+  private ButtonGroup group;
+  private JButton submitBtn;
+  private JButton quitBtn;
+
+  private JPanel centerPanel;
+  private JPanel bottomPanel;
+
+  public ExamFrame(Paper paper, Login.Account user) {
+    this.paper = paper;
+    this.user = user;
+
+    setTitle("答题 - " + user.username);
+    setSize(700, 400);
+    setLocationRelativeTo(null);
+    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+
+    qLabel = new JLabel("", SwingConstants.LEFT);
+    qLabel.setFont(new Font("Serif", Font.PLAIN, 16));
+    JPanel top = new JPanel(new BorderLayout());
+    top.setBorder(BorderFactory.createEmptyBorder(10,10,10,10));
+    top.add(qLabel, BorderLayout.CENTER);
+
+    centerPanel = new JPanel(new GridLayout(4,1,6,6));
+    group = new ButtonGroup();
+    for (int i=0;i<4;i++){
+      radioBtns[i] = new JRadioButton();
+      group.add(radioBtns[i]);
+      centerPanel.add(radioBtns[i]);
+    }
+
+    bottomPanel = new JPanel(new FlowLayout(FlowLayout.RIGHT));
+    submitBtn = new JButton("提交当前题");
+    quitBtn = new JButton("结束并查看成绩");
+    bottomPanel.add(quitBtn);
+    bottomPanel.add(submitBtn);
+
+    add(top, BorderLayout.NORTH);
+    add(centerPanel, BorderLayout.CENTER);
+    add(bottomPanel, BorderLayout.SOUTH);
+
+    submitBtn.addActionListener(e -> submitAnswer());
+    quitBtn.addActionListener(e -> finishExam());
+
+    showQuestion();
+    setVisible(true);
+  }
+
+  /** 显示一道题 */
+  private void showQuestion() {
+    if (index >= paper.size()) {
+      showSubmitPage();
+      return;
+    }
+    String q = paper.questions.get(index);
+    qLabel.setText("<html><b>第 " + (index+1) + " 题：</b> " + q + "</html>");
+    String[] opts = paper.options.get(index);
+
+    for (int i=0;i<4;i++) {
+      radioBtns[i].setText(opts[i]);
+    }
+    // 清除上一次选择
+    group.clearSelection();
+  }
+
+  /** 提交当前题 */
+  private void submitAnswer() {
+    int selected = -1;
+    for (int i=0;i<4;i++) if (radioBtns[i].isSelected()) selected = i;
+    if (selected == -1) {
+      JOptionPane.showMessageDialog(this, "请选择一个选项后再提交");
+      return;
+    }
+    // 判断对错
+    if (selected == paper.correctIndex[index]) score++;
+
+    index++;
+    if (index < paper.size()) {
+      showQuestion();
+    } else {
+      // 做完所有题 → 显示提交确认页面
+      showSubmitPage();
+    }
+  }
+
+  /** 做完所有题目后显示确认提交界面 */
+  private void showSubmitPage() {
+    // 移除中间题目区域和按钮
+    getContentPane().remove(centerPanel);
+    getContentPane().remove(bottomPanel);
+
+    JLabel finishLabel = new JLabel("已完成所有题目，是否确认提交？", SwingConstants.CENTER);
+    finishLabel.setFont(new Font("Serif", Font.BOLD, 18));
+    add(finishLabel, BorderLayout.CENTER);
+
+    JPanel confirmPanel = new JPanel(new FlowLayout(FlowLayout.CENTER));
+    JButton confirmBtn = new JButton("确认提交");
+    JButton cancelBtn = new JButton("返回最后一题");
+    confirmPanel.add(cancelBtn);
+    confirmPanel.add(confirmBtn);
+    add(confirmPanel, BorderLayout.SOUTH);
+
+    confirmBtn.addActionListener(e -> finishExam());
+    cancelBtn.addActionListener(e -> {
+      // 返回最后一题继续查看/修改
+      getContentPane().remove(finishLabel);
+      getContentPane().remove(confirmPanel);
+      add(centerPanel, BorderLayout.CENTER);
+      add(bottomPanel, BorderLayout.SOUTH);
+      index = paper.size() - 1;
+      showQuestion();
+      revalidate();
+      repaint();
+    });
+
+    revalidate();
+    repaint();
+  }
+
+  /** 完成考试 → 进入成绩界面 */
+  private void finishExam() {
+    int total = paper.size();
+    double percent = total==0 ? 0 : (100.0 * score / total);
+    dispose();
+    new ResultFrame(user, score, total, percent);
+  }
+}

src/view/ExamSetupFrame.java

@@ -0,0 +1,63 @@
+package view;
+
+import javax.swing.*;
+import java.awt.*;
+import controller.FunctionController;
+import model.Login;
+import model.LanguageSwitch;
+
+/**
+ * 出题设置：选择/切换难度（显示当前账户默认难度），输入题数（10-30）
+ */
+public class ExamSetupFrame extends JFrame {
+  private JTextField numberField;
+  private JComboBox<String> levelBox;
+  private FunctionController controller;
+  private Login.Account user;
+
+  public ExamSetupFrame(Login.Account user) {
+    this.user = user;
+    this.controller = new FunctionController(user);
+
+    setTitle("出题设置 - " + user.username);
+    setSize(380, 200);
+    setLocationRelativeTo(null);
+    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+
+    JPanel p = new JPanel(new GridLayout(4,2,8,8));
+    p.setBorder(BorderFactory.createEmptyBorder(8,8,8,8));
+    p.add(new JLabel("当前难度:"));
+    levelBox = new JComboBox<>(new String[]{"小学","初中","高中"});
+    levelBox.setSelectedItem(LanguageSwitch.levelToChinese(user.level));
+    p.add(levelBox);
+
+    p.add(new JLabel("输入题目数量 (10-30):"));
+    numberField = new JTextField("10");
+    p.add(numberField);
+
+    JButton startBtn = new JButton("开始出题");
+    JButton backBtn = new JButton("返回登录");
+    p.add(startBtn);
+    p.add(backBtn);
+
+    add(p);
+
+    startBtn.addActionListener(e -> {
+      try {
+        int n = Integer.parseInt(numberField.getText().trim());
+        // 更新用户难度为界面选择
+        String lv = (String) levelBox.getSelectedItem();
+        Login.Level newLv = LanguageSwitch.chineseToLevel(lv);
+        user.level = newLv;
+        controller.startExam(n);
+        dispose();
+      } catch (NumberFormatException ex) {
+        JOptionPane.showMessageDialog(this, "请输入有效整数");
+      }
+    });
+
+    backBtn.addActionListener(e -> { dispose(); new LoginFrame(); });
+
+    setVisible(true);
+  }
+}

src/view/LoginFrame.java

@@ -0,0 +1,68 @@
+package view;
+
+import javax.swing.*;
+import java.awt.*;
+import model.Login;
+import controller.AssignController;
+
+/**
+ * 登录窗口
+ */
+public class LoginFrame extends JFrame {
+
+  private JTextField usernameField;
+  private JPasswordField passwordField;
+
+  public LoginFrame() {
+    setTitle("数学卷子生成器 - 登录");
+    setSize(380, 220);
+    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+    setLocationRelativeTo(null);
+
+    JPanel p = new JPanel(new GridLayout(4, 2, 8, 8));
+    p.setBorder(BorderFactory.createEmptyBorder(10,10,10,10));
+    p.add(new JLabel("用户名:"));
+    usernameField = new JTextField();
+    p.add(usernameField);
+
+    p.add(new JLabel("密码:"));
+    passwordField = new JPasswordField();
+    p.add(passwordField);
+
+    JButton loginBtn = new JButton("登录");
+    JButton regBtn = new JButton("注册");
+    JButton exitBtn = new JButton("退出");
+
+    p.add(loginBtn);
+    p.add(regBtn);
+    p.add(new JLabel());
+    p.add(exitBtn);
+
+    add(p);
+
+    loginBtn.addActionListener(e -> {
+      String u = usernameField.getText().trim();
+      String pwd = new String(passwordField.getPassword()).trim();
+      if (u.isEmpty() || pwd.isEmpty()) {
+        JOptionPane.showMessageDialog(this, "请输入用户名和密码", "提示", JOptionPane.INFORMATION_MESSAGE);
+        return;
+      }
+      Login.Account acc = Login.login(u, pwd);
+      if (acc != null) {
+        dispose();
+        new MainMenuFrame(acc); // 登录后先进入主菜单
+      } else {
+        JOptionPane.showMessageDialog(this, "用户名或密码错误", "登录失败", JOptionPane.ERROR_MESSAGE);
+      }
+
+    });
+
+    regBtn.addActionListener(e -> {
+      new RegisterFrame(this);
+    });
+
+    exitBtn.addActionListener(e -> System.exit(0));
+
+    setVisible(true);
+  }
+}

src/view/MainMenuFrame.java

@@ -0,0 +1,59 @@
+package view;
+
+import javax.swing.*;
+import java.awt.*;
+import model.Login;
+
+/**
+ * 登录成功后的主菜单（可修改密码、开始出题、登出）
+ * 现在由 ExamSetupFrame 直接替代，但保留此类可拓展
+ */
+public class MainMenuFrame extends JFrame {
+  public MainMenuFrame(Login.Account user) {
+    setTitle("主菜单 - " + user.username);
+    setSize(400,200);
+    setLocationRelativeTo(null);
+    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+
+    JPanel p = new JPanel(new GridLayout(3,1,10,10));
+    JButton changePwd = new JButton("修改密码");
+    JButton start = new JButton("出题设置");
+    JButton logout = new JButton("退出登录");
+    p.add(start); p.add(changePwd); p.add(logout);
+    add(p);
+
+    start.addActionListener(e -> { new ExamSetupFrame(user); dispose(); });
+    changePwd.addActionListener(e -> new ChangePasswordDialog(this, user));
+    logout.addActionListener(e -> { dispose(); new LoginFrame(); });
+
+    setVisible(true);
+  }
+
+  // 内部类：修改密码对话框
+  static class ChangePasswordDialog extends JDialog {
+    public ChangePasswordDialog(JFrame owner, Login.Account user) {
+      super(owner, "修改密码", true);
+      setSize(350,200);
+      setLocationRelativeTo(owner);
+      JPanel p = new JPanel(new GridLayout(4,2,6,6));
+      p.setBorder(BorderFactory.createEmptyBorder(6,6,6,6));
+      p.add(new JLabel("旧密码:")); JPasswordField oldp = new JPasswordField(); p.add(oldp);
+      p.add(new JLabel("新密码:")); JPasswordField newp = new JPasswordField(); p.add(newp);
+      p.add(new JLabel("再次输入新密码:")); JPasswordField newp2 = new JPasswordField(); p.add(newp2);
+      JButton ok = new JButton("确定"); JButton cancel = new JButton("取消"); p.add(ok); p.add(cancel);
+      add(p);
+      ok.addActionListener(a -> {
+        String oldPwd = new String(oldp.getPassword()).trim();
+        String np = new String(newp.getPassword()).trim();
+        String np2 = new String(newp2.getPassword()).trim();
+        if (!np.equals(np2)) { JOptionPane.showMessageDialog(this, "两次密码不一致"); return; }
+        if (!Login.validatePasswordRules(np)) { JOptionPane.showMessageDialog(this, "密码不满足规则"); return; }
+        boolean okr = Login.changePassword(user.username, oldPwd, np);
+        if (okr) { JOptionPane.showMessageDialog(this, "修改成功"); dispose(); }
+        else JOptionPane.showMessageDialog(this, "旧密码错误");
+      });
+      cancel.addActionListener(a -> dispose());
+      setVisible(true);
+    }
+  }
+}

src/view/RegisterFrame.java

@@ -0,0 +1,149 @@
+package view;
+
+import javax.swing.*;
+import java.awt.*;
+import java.util.Properties;
+import java.util.Random;
+import jakarta.mail.*;
+import jakarta.mail.internet.*;
+import model.Login;
+import model.LanguageSwitch;
+
+/**
+ * 注册界面（使用 QQ 邮箱发送验证码）
+ */
+public class RegisterFrame extends JDialog {
+  private JTextField usernameField;
+  private JTextField emailField;
+  private JComboBox<String> levelBox;
+  private JPasswordField pwdField;
+  private JPasswordField pwdField2;
+  private JTextField codeField;
+  private String lastCode;
+
+  // QQ 邮箱配置
+  private static final String FROM_EMAIL = "songqifeng.sqf@qq.com";
+  private static final String AUTH_CODE = "gcyschltjgxedgjd"; // ⚠️ 在 QQ 邮箱里申请的授权码
+
+  public RegisterFrame(JFrame owner) {
+    super(owner, "注册新用户", true);
+    setSize(420, 320);
+    setLocationRelativeTo(owner);
+
+    JPanel p = new JPanel(new GridLayout(7, 2, 6, 6));
+    p.setBorder(BorderFactory.createEmptyBorder(8, 8, 8, 8));
+    p.add(new JLabel("用户名:"));
+    usernameField = new JTextField();
+    p.add(usernameField);
+
+    p.add(new JLabel("邮箱（接收注册码）:"));
+    emailField = new JTextField();
+    p.add(emailField);
+
+    p.add(new JLabel("年级:"));
+    levelBox = new JComboBox<>(new String[]{"小学", "初中", "高中"});
+    p.add(levelBox);
+
+    p.add(new JLabel("密码 (6-10位，含大小写与数字):"));
+    pwdField = new JPasswordField();
+    p.add(pwdField);
+
+    p.add(new JLabel("再次输入密码:"));
+    pwdField2 = new JPasswordField();
+    p.add(pwdField2);
+
+    JButton sendCodeBtn = new JButton("发送注册码");
+    p.add(sendCodeBtn);
+    codeField = new JTextField();
+    p.add(codeField);
+
+    JButton regBtn = new JButton("注册");
+    p.add(regBtn);
+    JButton cancelBtn = new JButton("取消");
+    p.add(cancelBtn);
+
+    add(p);
+
+    sendCodeBtn.addActionListener(e -> {
+      String email = emailField.getText().trim();
+      if (email.isEmpty() || !email.contains("@")) {
+        JOptionPane.showMessageDialog(this, "请输入有效邮箱");
+        return;
+      }
+      lastCode = String.format("%04d", new Random().nextInt(10000));
+      boolean sent = sendEmail(email, lastCode);
+      if (sent) {
+        JOptionPane.showMessageDialog(this, "注册码已发送，请检查邮箱。");
+      } else {
+        JOptionPane.showMessageDialog(this, "发送邮件失败，请检查网络或邮箱配置。");
+      }
+    });
+
+    regBtn.addActionListener(e -> {
+      String u = usernameField.getText().trim();
+      String email = emailField.getText().trim();
+      String pwd = new String(pwdField.getPassword()).trim();
+      String pwd2 = new String(pwdField2.getPassword()).trim();
+      String code = codeField.getText().trim();
+
+      if (u.isEmpty() || email.isEmpty() || pwd.isEmpty() || pwd2.isEmpty() || code.isEmpty()) {
+        JOptionPane.showMessageDialog(this, "请填写完整信息并输入注册码");
+        return;
+      }
+      if (!code.equals(lastCode)) {
+        JOptionPane.showMessageDialog(this, "注册码错误，请重新输入");
+        return;
+      }
+      if (!pwd.equals(pwd2)) {
+        JOptionPane.showMessageDialog(this, "两次密码不一致");
+        return;
+      }
+      if (!Login.validatePasswordRules(pwd)) {
+        JOptionPane.showMessageDialog(this, "密码不满足要求：6-10位且包含大写、小写和数字");
+        return;
+      }
+      String levelStr = (String) levelBox.getSelectedItem();
+      Login.Level lv = LanguageSwitch.chineseToLevel(levelStr);
+      boolean ok = Login.register(u, pwd, lv, email);
+      if (!ok) {
+        JOptionPane.showMessageDialog(this, "用户名已存在，请换一个用户名");
+        return;
+      }
+      JOptionPane.showMessageDialog(this, "注册成功，请用新用户登录");
+      dispose();
+    });
+
+    cancelBtn.addActionListener(e -> dispose());
+
+    setVisible(true);
+  }
+
+  private boolean sendEmail(String to, String code) {
+    try {
+      Properties props = new Properties();
+      props.put("mail.smtp.host", "smtp.qq.com");
+      props.put("mail.smtp.port", "465");
+      props.put("mail.smtp.auth", "true");
+      props.put("mail.smtp.ssl.enable", "true"); // ← 开启 SSL
+
+
+      Session session = Session.getInstance(props, new Authenticator() {
+        protected PasswordAuthentication getPasswordAuthentication() {
+          return new PasswordAuthentication(FROM_EMAIL, AUTH_CODE);
+        }
+      });
+
+      Message message = new MimeMessage(session);
+      message.setFrom(new InternetAddress(FROM_EMAIL));
+      message.setRecipients(Message.RecipientType.TO, InternetAddress.parse(to));
+      message.setSubject("数学卷子生成器 - 注册验证码");
+      message.setText("您的注册码为: " + code + "\n有效期 5 分钟。");
+
+      Transport.send(message);
+      return true;
+    } catch (Exception e) {
+      e.printStackTrace();
+      return false;
+    }
+  }
+}

src/view/ResultFrame.java

@@ -0,0 +1,39 @@
+package view;
+
+import javax.swing.*;
+import java.awt.*;
+import model.Login;
+
+/**
+ * 显示成绩并提供“退出或继续做题”的选择
+ */
+public class ResultFrame extends JFrame {
+  public ResultFrame(Login.Account user, int score, int total, double percent) {
+    setTitle("成绩 - " + user.username);
+    setSize(360,220);
+    setLocationRelativeTo(null);
+    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+
+    JPanel p = new JPanel(new GridLayout(5,1,6,6));
+    p.setBorder(BorderFactory.createEmptyBorder(10,10,10,10));
+    p.add(new JLabel("用户名: " + user.username));
+    p.add(new JLabel("得分: " + score + " / " + total));
+    p.add(new JLabel(String.format("百分比: %.2f%%", percent)));
+
+    JPanel btns = new JPanel(new FlowLayout());
+    JButton exit = new JButton("退出");
+    JButton again = new JButton("继续做题");
+    btns.add(again);
+    btns.add(exit);
+    p.add(btns);
+
+    add(p);
+    exit.addActionListener(e -> System.exit(0));
+    again.addActionListener(e -> {
+      dispose();
+      new ExamSetupFrame(user);
+    });
+
+    setVisible(true);
+  }
+}