补完所有的代码。

OOP/15Exam/3.10.cpp

@@ -0,0 +1,37 @@
+#include <cstring>
+#include <iostream>
+using namespace std;
+
+class A {
+public:
+    A(char *aa) {
+        b = strlen(aa);
+        a = new char[b + 1];
+        strcpy(a, aa);
+    }
+    ~A() {
+        delete[] a;
+    }
+    char *Geta() {
+        return a;
+    }
+    int Getb() {
+        return b;
+    }
+
+private:
+    char *a;
+    int b;
+};
+
+int main() {
+    A x("zhao"), y("zhuang");
+    cout << strlen(x.Geta()) << endl;
+    cout << strlen(y.Geta()) + x.Getb() << endl;
+    return 0;
+}
+
+/*
+4
+10
+*/

OOP/15Exam/3.7.cpp

@@ -0,0 +1,56 @@
+#include <iostream>
+using namespace std;
+
+class A {
+public:
+    A(int xx = 10) : x(xx) {
+        ++count;
+    }
+    virtual void show() const {
+        cout << count << " " << x << endl;
+    }
+    virtual ~A() {
+        cout << count-- << " " << x << endl;
+    }
+
+protected:
+    static int count;
+
+private:
+    int x;
+};
+
+class B : public A {
+public:
+    B(int xx, int yy) : A(xx), y(yy) {
+        y += 8;
+    }
+    virtual void show() const {
+        cout << count << " " << y << endl;
+    }
+    virtual ~B() {
+        cout << count << " " << y << endl;
+    }
+
+private:
+    int y;
+};
+
+int A::count = 0;
+
+int main() {
+    A *ptr[] = {new B(66, 88), new A};
+    ptr[0]->show();
+    ptr[1]->show();
+    delete ptr[0];
+    delete ptr[1];
+    return 0;
+}
+
+/*
+2 96
+2 10
+2 96
+2 66
+1 10
+*/

OOP/15Exam/3.8.cpp

@@ -0,0 +1,26 @@
+#include <iostream>
+using namespace std;
+class A {
+public:
+    A(int x = 0) : r1(x){};
+    void print() {
+        cout << 'E' << r1 << '-';
+    }
+    void print(int x) {
+        cout << 'P' << r1 * r1 * r1 + x << '-';
+    }
+
+private:
+    int r1;
+};
+
+int main() {
+    A a1(3), a2(9);
+    a1.print(1);
+    a2.print();
+    return 0;
+}
+
+/*
+P28-E9-
+*/

OOP/15Exam/3.9.cpp

@@ -0,0 +1,42 @@
+#include <cstring>
+#include <iostream>
+using namespace std;
+class A {
+public:
+    A(char *name = "HSW") {
+        strcpy(this->name, name);
+    }
+    const char *getName() const {
+        return name;
+    }
+    virtual char *getAddress() const {
+        return "BEIDA";
+    }
+
+private:
+    char name[20];
+};
+
+class AB : public A {
+public:
+    AB(char *name) : A(name){};
+    virtual char *getAddress() const {
+        return "TSINGHUA";
+    }
+};
+
+int main() {
+    A *gs[] = {new AB("ZHT"), new A}, **p = gs + 1;
+    cout << (*p)->getName() << "STAY IN" << (*p)->getAddress() << endl;
+    p--;
+    cout << (*p)->getName() << "STAY IN" << (*p)->getAddress() << endl;
+    for (int i = 0; i < 2; i++) {
+        delete gs[i];
+    }
+    return 0;
+}
+
+/*
+HSWSTAY INBEIDA
+ZHTSTAY INTSINGHUA
+*/