ADD file via upload

src/AbstractQuestionGenerator.java

@@ -0,0 +1,134 @@
+import java.io.*;
+import java.util.HashSet;
+import java.util.Random;
+import java.util.Set;
+import java.util.Stack;
+
+public abstract class AbstractQuestionGenerator implements QuestionGenerator {
+	
+	protected Random random = new Random();
+    protected Set<String> generatedQuestions = new HashSet<>();
+    protected String username;
+    
+    // 设置用户名用于查重
+    public void setUsername(String username) {
+        this.username = username;
+        loadExistingQuestions();
+    }
+    
+    // 从文件中加载已存在的题目
+    protected void loadExistingQuestions() {
+        if (username == null) return;
+        
+        File[] userFiles = QuestionManager.getUserQuestionFiles(username);
+        for (File file : userFiles) {
+            try (BufferedReader reader = new BufferedReader(new FileReader(file))) {
+                String line;
+                while ((line = reader.readLine()) != null) {
+                    line = line.trim();
+                    if (!line.isEmpty() && line.matches("^\\d+\\. .+")) {
+                        // 提取题目内容（去除题号）
+                        String question = line.replaceFirst("^\\d+\\. ", "");
+                        String normalized = normalizeQuestion(question);
+                        generatedQuestions.add(normalized);
+                    }
+                }
+            } catch (IOException e) {
+                System.out.println("读取题目文件出错: " + e.getMessage());
+            }
+        }
+    }
+    
+    // 标准化题目格式用于比较
+    public String normalizeQuestion(String question) {
+        return question.replaceAll("\\s+", "");
+    }
+    
+    protected String generateNumber() {
+        return String.valueOf(random.nextInt(100) + 1);
+    }
+    
+    public String generateOperator(String[] operators) {
+        return operators[random.nextInt(operators.length)];
+    }
+    
+    protected boolean isQuestionUnique(String question) {
+        String normalized = normalizeQuestion(question);
+        return !generatedQuestions.contains(normalized);
+    }
+    
+    protected void addToGeneratedQuestions(String question) {
+        String normalized = normalizeQuestion(question);
+        generatedQuestions.add(normalized);
+    }
+    
+    
+    protected boolean hasBalancedParentheses(String expression) {
+        Stack<Character> stack = new Stack<>();
+        for (char c : expression.toCharArray()) {
+            if (c == '(') {
+                stack.push(c);
+            } else if (c == ')') {
+                if (stack.isEmpty()) return false;
+                stack.pop();
+            }
+        }
+        return stack.isEmpty();
+    }
+    
+    public boolean isValidParentheses(String expression) {
+        expression = expression.replaceAll("\\s+", "");
+        
+        if (!hasBalancedParentheses(expression)) {
+            return false;
+        }
+        
+        if (expression.startsWith("(") && expression.endsWith(")") && 
+            hasBalancedParentheses(expression.substring(1, expression.length() - 1))) {
+            return false;
+        }
+        
+        String[] parts = expression.split("[+\\-×÷]");
+        for (String part : parts) {
+            part = part.trim();
+            if (part.startsWith("(") && part.endsWith(")")) {
+                String inside = part.substring(1, part.length() - 1);
+                if (isSimpleOperand(inside)) {
+                    return false;
+                }
+            }
+        }
+        
+        return true;
+    }
+    
+    private boolean isSimpleOperand(String str) {
+        return str.matches("\\d+")  || str.matches("√\\d+") || str.matches("\\d²+") || 
+               str.matches("sin[\\d°]+") || str.matches("cos[\\d°]+") || str.matches("tan[\\d°]+") ||
+               str.matches("sincos[\\d°]+") || str.matches("sintan[\\d°]+") || str.matches("cossin[\\d°]+") ||
+               str.matches("costan[\\d°]+") || str.matches("tansin[\\d°]+") || str.matches("tancos[\\d°]+");
+    }
+    
+    protected boolean hasOperator(String expression) {
+        return expression.contains("+") || expression.contains("-") || 
+               expression.contains("×") || expression.contains("÷");
+    }
+    
+    protected String ensureBalancedParentheses(String expression) {
+        int openCount = 0;
+        int closeCount = 0;
+        
+        for (char c : expression.toCharArray()) {
+            if (c == '(') openCount++;
+            if (c == ')') closeCount++;
+        }
+        
+        while (openCount > closeCount) {
+            expression += ")";
+            closeCount++;
+        }
+        
+        return expression;
+    }
+    
+}