day4: homework

day4/d7.cpp

@@ -0,0 +1,183 @@
+#include <iostream>
+#include <cstring>
+#include <cstdlib>
+
+using namespace std;
+
+// 声明遥控器类
+class Remote;
+
+// 定义电视类
+class Television
+{
+    friend class Remote;
+
+public:
+    enum
+    {
+        On, // 电视开关状态
+        Off
+    };
+    enum
+    {
+        minVol,
+        maxVol = 100 // 音量从 0 到 100
+    };
+    enum
+    {
+        minChannel = 1,
+        maxChannel = 255 // 频道范围 1 到 255
+    };
+
+    Television()
+    {
+        mStatus = Off;         // 状态
+        mVolume = minVol;      // 声音
+        mChannel = minChannel; // 频道
+    }
+
+public:
+    void power() // 开关机
+    {
+        this->mStatus = (this->mStatus == On ? Off : On);
+    }
+
+    void VolumeUp() // 调高音量
+    {
+        if (this->mVolume >= maxVol)
+            return;
+        this->mVolume++;
+    }
+
+    void VolumeDown() // 调低音量
+    {
+        if (this->mVolume <= minVol)
+            return;
+        this->mVolume--;
+    }
+
+    void ChannelUp() // 向上更换电视频道
+    {
+        if (this->mChannel >= maxChannel)
+            return;
+        this->mChannel++;
+    }
+
+    void ChannelDown() // 向下更换电视频道
+    {
+        if (this->mChannel <= minChannel)
+            return;
+        this->mChannel--;
+    }
+
+    void ShowTeleState() // 展示当前电视状态信息
+    {
+        cout << "开机状态: " << (mStatus == On ? "已开机" : "已关机") << endl;
+        if (mStatus == On)
+        {
+            cout << "当前音量: " << mVolume << endl;
+            cout << "当前频道: " << mChannel << endl;
+        }
+        cout << "----------------------" << endl;
+    }
+
+private:
+    int mStatus;  // 电视状态
+    int mVolume;  // 声音
+    int mChannel; // 频道
+};
+
+// 定义遥控器
+class Remote
+{
+public:
+    Remote(Television *tv) // 构造函数
+    {
+        pTV = tv;
+    }
+
+public:
+    void power() // 开关机
+    {
+        pTV->power();
+    }
+
+    void VolumeUp() // 调高音量
+    {
+        pTV->VolumeUp();
+    }
+
+    void VolumeDown() // 调低音量
+    {
+        pTV->VolumeDown();
+    }
+
+    void ChannelUp() // 向上更换电视频道
+    {
+        pTV->ChannelUp();
+    }
+
+    void ChannelDown() // 向下更换电视频道
+    {
+        pTV->ChannelDown();
+    }
+
+    // 设置频道，遥控器新增功能
+    void SetChannel(int channel)
+    {
+        if (channel < Television::minChannel || channel > Television::maxChannel)
+            return;
+        pTV->mChannel = channel;
+    }
+
+    void ShowTeleState() // 展示当前电视状态信息
+    {
+        pTV->ShowTeleState();
+    }
+
+private:
+    Television *pTV;
+};
+
+// 直接操作电视
+void test01()
+{
+    Television tv;
+    tv.ShowTeleState();
+    tv.power();    // 开机
+    tv.VolumeUp(); // 音量 +1
+    tv.VolumeUp();
+    tv.VolumeUp();
+    tv.VolumeUp();
+    tv.ChannelUp(); // 频道 +1
+    tv.ChannelUp();
+    tv.ShowTeleState();
+}
+
+// 通过遥控器操作电视
+void test02()
+{
+    // 创建电视
+    Television tv;
+
+    // 创建遥控器
+    Remote rmt(&tv);
+
+    rmt.ShowTeleState();
+    rmt.power();    // 开机
+    rmt.VolumeUp(); // 音量 +1
+    rmt.VolumeUp();
+    rmt.VolumeUp();
+    rmt.VolumeUp();
+    rmt.ChannelUp(); // 频道 +1
+    rmt.ChannelUp();
+    rmt.SetChannel(100);
+    rmt.ShowTeleState();
+}
+
+int main()
+{
+    // test01();
+    test02();
+    return 0;
+}

day4/homework/h1.cpp

@@ -0,0 +1,24 @@
+// 如下程序运行的结果是什么 ? 是否存在错误，如果有错请指出并分析原因。
+#include <iostream>
+
+using namespace std;
+
+class Abc
+{
+private:
+    int rN;
+
+public:
+    Abc(int x) : rN(x) {}
+    static void print()
+    {
+        Abc abc(20);
+        cout << abc.rN << endl;
+    }
+};
+
+int main()
+{
+    Abc::print();
+    return 0;
+}

day4/homework/h2.cpp

@@ -0,0 +1,67 @@
+// 设已经有A,B,C,D 4个类的定义，程序中A,B,C,D析构函数调用顺序为（   ）
+#include <iostream>
+#include <cstring>
+#include <cstdlib>
+
+using namespace std;
+
+class A
+{
+public:
+    A() { cout << "A()" << endl; }
+    ~A()
+    {
+        cout << "~A()" << endl;
+    }
+};
+
+class B
+{
+public:
+    B() { cout << "B()" << endl; }
+    ~B()
+    {
+        cout << "~B()" << endl;
+    }
+};
+
+class C
+{
+public:
+    C() { cout << "C()" << endl; }
+    ~C()
+    {
+        cout << "~C()" << endl;
+    }
+};
+
+class D
+{
+public:
+    D() { cout << "D()" << endl; }
+    ~D()
+    {
+        cout << "~D()" << endl;
+    }
+};
+
+C c;
+
+int main()
+{
+    A *pa = new A();
+    B b;
+    static D d;
+    delete pa;
+}
+
+/* 
+C()
+A()
+B()
+D()
+~A() 
+~B() 
+~D() 
+~C()
+ */

day4/homework/h3.cpp

@@ -0,0 +1,35 @@
+// 运行以下程序，写出其输出的结果？
+#include <iostream>
+
+using namespace std;
+
+class Test
+{
+public:
+    Test(int i = 0)
+    {
+        cout << i;
+    }
+    Test(const Test &x)
+    {
+        cout << 2;
+    }
+    Test &operator=(const Test &x)
+    {
+        cout << 3;
+        return *this;
+    }
+    ~Test()
+    {
+        cout << 4;
+    }
+};
+
+int main()
+{
+    Test obj1(1), obj2(2);
+    Test obj3 = obj1;
+    return 0;
+}
+
+/* 122444 */

day4/homework/h4.cpp

@@ -0,0 +1,45 @@
+// 设计Car类，包含color（颜色）、weight(重量) 两个属性和一个带color和weight两个参数的构造函数、以及driver() 驾车、start() 启动、stop() 停车的函数。
+// 【提示】设计的类，可以在main() 自行测试
+#include <iostream>
+#include <cstring>
+#include <cstdlib>
+
+using namespace std;
+
+class Car
+{
+public:
+    Car(const string &color, int weight) : color(color), weight(weight) {}
+
+public:
+    void driver()
+    {
+        cout << "驾车 " << this->weight << " 车重" << endl;
+    }
+    void start()
+    {
+        cout << "启动 " << this->color << " 颜色的车" << endl;
+    }
+    void stop()
+    {
+        cout << "停车" << endl;
+    }
+
+private:
+    string color; // 颜色
+    int weight;   // 重量
+};
+
+void test()
+{
+    Car car("blue", 1200);
+    car.start();
+    car.driver();
+    car.stop();
+}
+
+int main()
+{
+    test();
+    return 0;
+}

day4/homework/h5.cpp

@@ -0,0 +1,79 @@
+// 继上面的Car类， 设计Person类，并设置Car类为Person类的友元类，使得在Person类的成员函数直接访问 Car对象的所有成员。
+// 【提示】Person类的构造函数传入 Car类的对象， 增加Person的成员函数用于操作Car类的成员函数或访问Car对象的属性。
+#include <iostream>
+#include <cstring>
+#include <cstdlib>
+
+using namespace std;
+
+class Car
+{
+    friend class Person;
+
+public:
+    Car(const string &color, int weight) : color(color), weight(weight) {}
+
+public:
+    void driver()
+    {
+        cout << "驾车 " << this->weight << " 车重" << endl;
+    }
+    void start()
+    {
+        cout << "启动 " << this->color << " 颜色的车" << endl;
+    }
+    void stop()
+    {
+        cout << "停车" << endl;
+    }
+
+private:
+    string color; // 颜色
+    int weight;   // 重量
+};
+
+class Person
+{
+    // friend class Car;
+
+public:
+    Person(Car &car) : tcar(car) {}
+
+public:
+    void setCarColor(const string &color)
+    {
+        // strcpy(tcar.color, color);
+        tcar.color = color;
+    }
+    void setCarWeight(int weight)
+    {
+        tcar.weight = weight;
+    }
+    void show()
+    {
+        cout << "驾驶着一辆" << tcar.color << ", 重" << tcar.weight << "千克的车辆" << endl;
+    }
+
+private:
+    Car &tcar;
+};
+
+void test()
+{
+    Car car("红色", 1000);
+    Person person(car);
+    person.setCarColor("蓝色");
+    person.setCarWeight(1230);
+
+    car.start();
+    car.driver();
+    car.stop();
+
+    person.show();
+}
+
+int main()
+{
+    test();
+    return 0;
+}

day4/homework/h6.cpp

@@ -0,0 +1,91 @@
+// 自定义ArrayList类，实现线性列表（类似数组）结构的数据元素操作。操作方法：
+//     1. add(int) 添加int整型的数据元素
+//     2. remove(int) 删除数据元素
+//     3. int get(int index) 获取指定位置的元素
+//     4. void print() 打印列表中所有元素
+//     5. int size() 返回列表的当前大小
+//     6. void sort(bool reversed = false) 元素排序，reversed为true时，表示从大小到小，反之，表示从小到到。
+#include <iostream>
+#include <cstring>
+#include <cstdlib>
+#include <vector>
+#include <algorithm>
+
+using namespace std;
+
+class ArrayList
+{
+private:
+    vector<int> elements; // 动态数组元素
+
+public:
+    void add(int value) // 添加 int 整型的数据元素
+    {
+        elements.push_back(value);
+    }
+    void remove(int index) // 删除数据元素
+    {
+        int size = elements.size();
+        if (index >= 0 && index < size)
+            elements.erase(elements.begin() + index);
+    }
+    int get(int index) // 获取指定位置的元素
+    {
+        int size = elements.size();
+        if (index >= 0 && index < size)
+            return elements[index];
+        return -1; // 返回无效索引，表示未找到元素
+    }
+    void print() // 打印列表中的所有元素
+    {
+        for (int i = 0; i < elements.size(); i++)
+            cout << elements[i] << " ";
+    }
+    int size() // 返回列表的当前大小
+    {
+        return elements.size();
+    }
+    void sort(bool reversed = false) // 默认从小到大排序，当reversed 为 true 时，从大到小排序
+    {
+        if (reversed == true)
+            std::sort(elements.rbegin(), elements.rend());
+        else
+            std::sort(elements.begin(), elements.end());
+    }
+};
+
+int main()
+{
+    ArrayList list;
+
+    list.add(5);
+    list.add(2);
+    list.add(8);
+    list.add(9);
+    list.add(13);
+
+    cout << "原始列表: ";
+    list.print();
+    cout << endl;
+
+    cout << "列表大小为: " << list.size() << endl;
+
+    cout << "删除第二位的元素后显示为: ";
+    list.remove(2);
+    list.print();
+    cout << endl;
+
+    cout << "此时第二位的元素为: " << list.get(2) << endl;
+
+    cout << "从大到小排序后列表为: ";
+    list.sort(true);
+    list.print();
+    cout << endl;
+
+    cout << "从小到大排序后列表为: ";
+    list.sort();
+    list.print();
+    cout << endl;
+
+    return 0;
+}

day4/homework/h6_2.cpp

@@ -0,0 +1,136 @@
+#include <iostream>
+
+class ArrayList
+{
+private:
+    int *elements; // 存储元素的数组
+    int capacity;  // 数组的容量
+    int count;     // 当前元素的数量
+
+public:
+    ArrayList()
+    {
+        capacity = 10; // 初始容量为10
+        elements = new int[capacity];
+        count = 0;
+    }
+
+    ~ArrayList()
+    {
+        delete[] elements;
+    }
+
+    void add(int value)
+    {
+        if (count == capacity)
+        {
+            // 如果数组已满，扩展容量为原来的两倍
+            int newCapacity = capacity * 2;
+            int *newElements = new int[newCapacity];
+            for (int i = 0; i < count; i++)
+            {
+                newElements[i] = elements[i];
+            }
+            delete[] elements;
+            elements = newElements;
+            capacity = newCapacity;
+        }
+        elements[count] = value;
+        count++;
+    }
+
+    void remove(int index)
+    {
+        if (index >= 0 && index < count)
+        {
+            for (int i = index; i < count - 1; i++)
+            {
+                elements[i] = elements[i + 1];
+            }
+            count--;
+        }
+    }
+
+    int get(int index)
+    {
+        if (index >= 0 && index < count)
+        {
+            return elements[index];
+        }
+        return -1; // 返回一个特殊值表示索引无效
+    }
+
+    void print()
+    {
+        for (int i = 0; i < count; i++)
+        {
+            std::cout << elements[i] << " ";
+        }
+        std::cout << std::endl;
+    }
+
+    int size()
+    {
+        return count;
+    }
+
+    void sort(bool reversed = false)
+    {
+        for (int i = 0; i < count - 1; i++)
+        {
+            for (int j = 0; j < count - i - 1; j++)
+            {
+                if (reversed)
+                {
+                    if (elements[j] < elements[j + 1])
+                    {
+                        int temp = elements[j];
+                        elements[j] = elements[j + 1];
+                        elements[j + 1] = temp;
+                    }
+                }
+                else
+                {
+                    if (elements[j] > elements[j + 1])
+                    {
+                        int temp = elements[j];
+                        elements[j] = elements[j + 1];
+                        elements[j + 1] = temp;
+                    }
+                }
+            }
+        }
+    }
+};
+
+int main()
+{
+    ArrayList list;
+
+    list.add(5);
+    list.add(2);
+    list.add(8);
+    list.add(1);
+
+    std::cout << "Original list: ";
+    list.print();
+
+    std::cout << "Size: " << list.size() << std::endl;
+
+    std::cout << "Element at index 2: " << list.get(2) << std::endl;
+
+    list.remove(1);
+
+    std::cout << "After removing element at index 1: ";
+    list.print();
+
+    std::cout << "Sorted list in ascending order: ";
+    list.sort();
+    list.print();
+
+    std::cout << "Sorted list in descending order: ";
+    list.sort(true);
+    list.print();
+
+    return 0;
+}