Lintcode: 形状工厂

 形状工厂

•  描述
•  笔记
•  数据
•  评测

工厂模式是一种常见的设计模式。实现一个形状工厂 ShapeFactory 来创建不同的形状类。这里我们假设只有三角形，正方形和矩形三种形状。

您在真实的面试中是否遇到过这个题？ 

Yes

样例

ShapeFactory sf = new ShapeFactory();Shape shape = sf.getShape("Square");shape.draw();>>  ---->> |    |>> |    |>>  ----shape = sf.getShape("Triangle");shape.draw();>>   /\>>  /  \>> /____\shape = sf.getShape("Rectangle");shape.draw();>>  ---->> |    |
>>  ----
** * Your object will be instantiated and called as such: * ShapeFactory* sf = new ShapeFactory(); * Shape* shape = sf->getShape(shapeType); * shape->draw(); */class Shape {public:    virtual void draw() const=0;};class Rectangle: public Shape {    // Write your code here    public:    void draw() const    {      printf(" ---- \n");      printf("|    |\n");      printf(" ---- \n");    }};class Square: public Shape {    // Write your code here      public:     void draw() const    {      printf(" ---- \n");      printf("|    |\n");      printf("|    |\n");      printf(" ---- \n");    }};class Triangle: public Shape {    // Write your code here     public:     void draw() const    {      printf("  /\\  \n");      printf(" /  \\ \n");      printf("/____\\\n");    }};class ShapeFactory {public:    /**     * @param shapeType a string     * @return Get object of type Shape     */    Shape* getShape(string& shapeType) {        // Write your code here        if(shapeType=="Square")          return new Square();        else if(shapeType=="Triangle")          return new Triangle();        else          return new Rectangle();    }};