diff --git a/Circle.java b/Circle.java
new file mode 100644
index 0000000..9691bcb
--- /dev/null
+++ b/Circle.java
@@ -0,0 +1,80 @@
+package challenge;
+
+import basic.Shape;
+import advanced.Resizable;
+
+/**
+ * 圆形类，实现Shape接口和Resizable接口
+ */
+public class Circle implements Shape, Resizable {
+    private String color;
+    private double radius;
+    
+    /**
+     * 构造方法
+     * @param color 圆形的颜色
+     * @param radius 圆形的半径
+     */
+    public Circle(String color, double radius) {
+        this.color = color;
+        this.radius = radius;
+    }
+    
+    @Override
+    public String getColor() {
+        return color;
+    }
+    
+    @Override
+    public double getArea() {
+        return Math.PI * radius * radius;
+    }
+    
+    @Override
+    public void display() {
+        System.out.println("Circle [color=" + color + ", radius=" + radius + ", area=" + getArea() + "]");
+    }
+    
+    @Override
+    public void enlarge(double factor) {
+        if (factor > 0) {
+            this.radius *= factor;
+        }
+    }
+    
+    @Override
+    public void shrink(double factor) {
+        if (factor > 0 && factor < 1) {
+            this.radius *= factor;
+        }
+    }
+    
+    @Override
+    public String getSizeInfo() {
+        return "Circle with radius: " + radius + ", area: " + getArea();
+    }
+    
+    /**
+     * 获取半径
+     * @return 半径
+     */
+    public double getRadius() {
+        return radius;
+    }
+    
+    /**
+     * 设置半径
+     * @param radius 新的半径
+     */
+    public void setRadius(double radius) {
+        this.radius = radius;
+    }
+    
+    /**
+     * 设置颜色
+     * @param color 新的颜色
+     */
+    public void setColor(String color) {
+        this.color = color;
+    }
+}
\ No newline at end of file
diff --git a/CircleToEllipseConverter.java b/CircleToEllipseConverter.java
new file mode 100644
index 0000000..b837760
--- /dev/null
+++ b/CircleToEllipseConverter.java
@@ -0,0 +1,60 @@
+package challenge;
+
+import basic.Shape;
+
+/**
+ * 圆形到椭圆形的转换器，实现ShapeConverter接口
+ */
+public class CircleToEllipseConverter implements ShapeConverter {
+    private double stretchFactor; // 拉伸因子，用于确定椭圆的长半轴
+    
+    /**
+     * 构造方法
+     * @param stretchFactor 拉伸因子，大于1时会将圆形拉伸成椭圆形
+     */
+    public CircleToEllipseConverter(double stretchFactor) {
+        this.stretchFactor = Math.max(stretchFactor, 1.0); // 确保拉伸因子至少为1
+    }
+    
+    @Override
+    public Shape convert(Shape sourceShape) {
+        if (!canConvert(sourceShape)) {
+            return null;
+        }
+        
+        Circle circle = (Circle) sourceShape;
+        double radius = circle.getRadius();
+        
+        // 将圆形转换为椭圆形：保持颜色不变，半径作为短半轴，拉伸后的半径作为长半轴
+        double semiMinorAxis = radius;
+        double semiMajorAxis = radius * stretchFactor;
+        
+        return new Ellipse(circle.getColor(), semiMajorAxis, semiMinorAxis);
+    }
+    
+    @Override
+    public boolean canConvert(Shape sourceShape) {
+        return sourceShape instanceof Circle;
+    }
+    
+    @Override
+    public String getConversionDescription() {
+        return "将圆形转换为椭圆形，拉伸因子为：" + stretchFactor;
+    }
+    
+    /**
+     * 获取拉伸因子
+     * @return 拉伸因子
+     */
+    public double getStretchFactor() {
+        return stretchFactor;
+    }
+    
+    /**
+     * 设置拉伸因子
+     * @param stretchFactor 新的拉伸因子
+     */
+    public void setStretchFactor(double stretchFactor) {
+        this.stretchFactor = Math.max(stretchFactor, 1.0);
+    }
+}
\ No newline at end of file
diff --git a/CompositeShape.java b/CompositeShape.java
new file mode 100644
index 0000000..477475c
--- /dev/null
+++ b/CompositeShape.java
@@ -0,0 +1,143 @@
+package challenge;
+
+import basic.Shape;
+import advanced.Resizable;
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * 复合图形类，实现Shape接口和Resizable接口，用于组合多个图形
+ */
+public class CompositeShape implements Shape, Resizable {
+    private String color;
+    private String name;
+    private List<Shape> shapes;
+    
+    /**
+     * 构造方法
+     * @param name 复合图形的名称
+     * @param color 复合图形的颜色
+     */
+    public CompositeShape(String name, String color) {
+        this.name = name;
+        this.color = color;
+        this.shapes = new ArrayList<>();
+    }
+    
+    /**
+     * 添加子图形
+     * @param shape 要添加的图形
+     */
+    public void addShape(Shape shape) {
+        if (shape != null) {
+            shapes.add(shape);
+        }
+    }
+    
+    /**
+     * 移除子图形
+     * @param shape 要移除的图形
+     * @return 如果移除成功则返回true，否则返回false
+     */
+    public boolean removeShape(Shape shape) {
+        return shapes.remove(shape);
+    }
+    
+    /**
+     * 移除所有子图形
+     */
+    public void clearShapes() {
+        shapes.clear();
+    }
+    
+    /**
+     * 获取子图形列表
+     * @return 子图形列表
+     */
+    public List<Shape> getShapes() {
+        return new ArrayList<>(shapes); // 返回副本，防止外部修改
+    }
+    
+    @Override
+    public String getColor() {
+        return color;
+    }
+    
+    @Override
+    public double getArea() {
+        double totalArea = 0.0;
+        for (Shape shape : shapes) {
+            totalArea += shape.getArea();
+        }
+        return totalArea;
+    }
+    
+    @Override
+    public void display() {
+        System.out.println("CompositeShape [name=" + name + ", color=" + color + ", totalShapes=" + shapes.size() + ", totalArea=" + getArea() + "]");
+        System.out.println("  子图形列表:");
+        for (int i = 0; i < shapes.size(); i++) {
+            System.out.print("  " + (i + 1) + ". ");
+            shapes.get(i).display();
+        }
+    }
+    
+    @Override
+    public void enlarge(double factor) {
+        if (factor > 0) {
+            for (Shape shape : shapes) {
+                if (shape instanceof Resizable) {
+                    ((Resizable) shape).enlarge(factor);
+                }
+            }
+        }
+    }
+    
+    @Override
+    public void shrink(double factor) {
+        if (factor > 0 && factor < 1) {
+            for (Shape shape : shapes) {
+                if (shape instanceof Resizable) {
+                    ((Resizable) shape).shrink(factor);
+                }
+            }
+        }
+    }
+    
+    @Override
+    public String getSizeInfo() {
+        return "CompositeShape '" + name + "' with " + shapes.size() + " shapes, total area: " + getArea();
+    }
+    
+    /**
+     * 获取复合图形的名称
+     * @return 名称
+     */
+    public String getName() {
+        return name;
+    }
+    
+    /**
+     * 设置复合图形的名称
+     * @param name 新的名称
+     */
+    public void setName(String name) {
+        this.name = name;
+    }
+    
+    /**
+     * 设置颜色
+     * @param color 新的颜色
+     */
+    public void setColor(String color) {
+        this.color = color;
+    }
+    
+    /**
+     * 获取子图形的数量
+     * @return 子图形数量
+     */
+    public int getShapeCount() {
+        return shapes.size();
+    }
+}
\ No newline at end of file
diff --git a/Ellipse.java b/Ellipse.java
new file mode 100644
index 0000000..c8d588e
--- /dev/null
+++ b/Ellipse.java
@@ -0,0 +1,101 @@
+package challenge;
+
+import basic.Shape;
+import advanced.Resizable;
+
+/**
+ * 椭圆形类，实现Shape接口和Resizable接口
+ */
+public class Ellipse implements Shape, Resizable {
+    private String color;
+    private double semiMajorAxis; // 长半轴
+    private double semiMinorAxis; // 短半轴
+    
+    /**
+     * 构造方法
+     * @param color 椭圆形的颜色
+     * @param semiMajorAxis 长半轴
+     * @param semiMinorAxis 短半轴
+     */
+    public Ellipse(String color, double semiMajorAxis, double semiMinorAxis) {
+        this.color = color;
+        this.semiMajorAxis = Math.max(semiMajorAxis, semiMinorAxis); // 确保长半轴不小于短半轴
+        this.semiMinorAxis = Math.min(semiMajorAxis, semiMinorAxis);
+    }
+    
+    @Override
+    public String getColor() {
+        return color;
+    }
+    
+    @Override
+    public double getArea() {
+        return Math.PI * semiMajorAxis * semiMinorAxis;
+    }
+    
+    @Override
+    public void display() {
+        System.out.println("Ellipse [color=" + color + ", semiMajorAxis=" + semiMajorAxis + ", semiMinorAxis=" + semiMinorAxis + ", area=" + getArea() + "]");
+    }
+    
+    @Override
+    public void enlarge(double factor) {
+        if (factor > 0) {
+            this.semiMajorAxis *= factor;
+            this.semiMinorAxis *= factor;
+        }
+    }
+    
+    @Override
+    public void shrink(double factor) {
+        if (factor > 0 && factor < 1) {
+            this.semiMajorAxis *= factor;
+            this.semiMinorAxis *= factor;
+        }
+    }
+    
+    @Override
+    public String getSizeInfo() {
+        return "Ellipse with semi-major axis: " + semiMajorAxis + ", semi-minor axis: " + semiMinorAxis + ", area: " + getArea();
+    }
+    
+    /**
+     * 获取长半轴
+     * @return 长半轴
+     */
+    public double getSemiMajorAxis() {
+        return semiMajorAxis;
+    }
+    
+    /**
+     * 设置长半轴
+     * @param semiMajorAxis 新的长半轴
+     */
+    public void setSemiMajorAxis(double semiMajorAxis) {
+        this.semiMajorAxis = semiMajorAxis;
+    }
+    
+    /**
+     * 获取短半轴
+     * @return 短半轴
+     */
+    public double getSemiMinorAxis() {
+        return semiMinorAxis;
+    }
+    
+    /**
+     * 设置短半轴
+     * @param semiMinorAxis 新的短半轴
+     */
+    public void setSemiMinorAxis(double semiMinorAxis) {
+        this.semiMinorAxis = semiMinorAxis;
+    }
+    
+    /**
+     * 设置颜色
+     * @param color 新的颜色
+     */
+    public void setColor(String color) {
+        this.color = color;
+    }
+}
\ No newline at end of file
diff --git a/ShapeConversionSystem.java b/ShapeConversionSystem.java
new file mode 100644
index 0000000..4adb254
--- /dev/null
+++ b/ShapeConversionSystem.java
@@ -0,0 +1,109 @@
+package challenge;
+
+import basic.Shape;
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * 图形转换系统，用于管理和执行图形转换
+ */
+public class ShapeConversionSystem {
+    private List<ShapeConverter> converters;
+    
+    /**
+     * 构造方法
+     */
+    public ShapeConversionSystem() {
+        this.converters = new ArrayList<>();
+    }
+    
+    /**
+     * 添加图形转换器
+     * @param converter 要添加的转换器
+     */
+    public void addConverter(ShapeConverter converter) {
+        if (converter != null && !converters.contains(converter)) {
+            converters.add(converter);
+        }
+    }
+    
+    /**
+     * 移除图形转换器
+     * @param converter 要移除的转换器
+     * @return 如果移除成功则返回true，否则返回false
+     */
+    public boolean removeConverter(ShapeConverter converter) {
+        return converters.remove(converter);
+    }
+    
+    /**
+     * 查找可以转换指定图形的转换器
+     * @param sourceShape 源图形
+     * @return 可以转换该图形的转换器列表
+     */
+    public List<ShapeConverter> findSuitableConverters(Shape sourceShape) {
+        List<ShapeConverter> suitableConverters = new ArrayList<>();
+        for (ShapeConverter converter : converters) {
+            if (converter.canConvert(sourceShape)) {
+                suitableConverters.add(converter);
+            }
+        }
+        return suitableConverters;
+    }
+    
+    /**
+     * 使用指定的转换器转换图形
+     * @param converter 要使用的转换器
+     * @param sourceShape 源图形
+     * @return 转换后的图形，如果转换失败则返回null
+     */
+    public Shape convert(ShapeConverter converter, Shape sourceShape) {
+        if (converter != null && converter.canConvert(sourceShape)) {
+            return converter.convert(sourceShape);
+        }
+        return null;
+    }
+    
+    /**
+     * 使用第一个合适的转换器转换图形
+     * @param sourceShape 源图形
+     * @return 转换后的图形，如果没有合适的转换器则返回null
+     */
+    public Shape convert(Shape sourceShape) {
+        List<ShapeConverter> suitableConverters = findSuitableConverters(sourceShape);
+        if (!suitableConverters.isEmpty()) {
+            return suitableConverters.get(0).convert(sourceShape);
+        }
+        return null;
+    }
+    
+    /**
+     * 获取所有可用的转换器
+     * @return 转换器列表
+     */
+    public List<ShapeConverter> getAllConverters() {
+        return new ArrayList<>(converters);
+    }
+    
+    /**
+     * 显示所有可用的转换器信息
+     */
+    public void displayAvailableConverters() {
+        System.out.println("===== 可用的图形转换器 =====");
+        if (converters.isEmpty()) {
+            System.out.println("暂无可用的转换器");
+        } else {
+            for (int i = 0; i < converters.size(); i++) {
+                System.out.println((i + 1) + ". " + converters.get(i).getConversionDescription());
+            }
+        }
+        System.out.println("=============================");
+    }
+    
+    /**
+     * 清空所有转换器
+     */
+    public void clearConverters() {
+        converters.clear();
+    }
+}
\ No newline at end of file
diff --git a/ShapeConverter.java b/ShapeConverter.java
new file mode 100644
index 0000000..7738010
--- /dev/null
+++ b/ShapeConverter.java
@@ -0,0 +1,28 @@
+package challenge;
+
+import basic.Shape;
+
+/**
+ * 图形转换接口，定义图形之间的转换行为
+ */
+public interface ShapeConverter {
+    /**
+     * 将源图形转换为目标图形
+     * @param sourceShape 源图形
+     * @return 转换后的目标图形，如果转换不支持则返回null
+     */
+    Shape convert(Shape sourceShape);
+    
+    /**
+     * 检查是否支持从源图形类型转换到目标图形类型
+     * @param sourceShape 源图形
+     * @return 如果支持转换则返回true，否则返回false
+     */
+    boolean canConvert(Shape sourceShape);
+    
+    /**
+     * 获取转换的描述信息
+     * @return 转换描述
+     */
+    String getConversionDescription();
+}
\ No newline at end of file