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| 删除的内容标记成这样。 | 加入的内容标记成这样。 |
| 行号 7: | 行号 7: |
| const int size; size = 10; |
const int size= 10; |
找出以下程序中的语法错误，并作出解释。
1 #include <stdlib.h> 2 int main() { 3 const int size= 10; 4 int a[size]; 5 int *p1 = new int[size]; 6 int *p2 = malloc(sizeof(int)* size); 7 int *p3 = new int(size); 8 for(int i = 0; i < size; i++) { 9 a[i] = i; 10 p1[i] = a[i] * i; 11 p2[i] = p1[i] * i; 12 p3[i] = p2[i] * i; 13 } 14 int sum; 15 for(int i = 0; i < size; i++) 16 sum += a[i] + p1[i] + p2[i] + p3[i]; 17 cout << sum; 18 delete p1; 19 delete [] p2; 20 delete p3; 21 }
1 #include <iostream> 2 using namespace std; 3 class N { 4 static int n = 0; 5 int i; 6 public: 7 void N() : i(0) { } 8 void N(int a = 0) : i (a) { } 9 void N(int a = 0, int b) : i(a), n(b) { } 10 int get() const { return i++; } 11 void set(int a) { i = a;} 12 void print() const { cout << get() << endl;} 13 static int getn() const { return n; } 14 static void setn(int a) { n = a; i++; } 15 } 16 int main() { 17 cout << N::n << endl; 18 cout << N::getn() << endl; 19 cout << get() << endl; 20 cout << N::get() << endl; 21 cout << N::setn(10) << endl; 22 N *p = new N(5); 23 N n(); 24 n.set(10); 25 n.setn(11); 26 p.set(5); 27 delete p; 28 }
1 #include <string> 2 #include <iostream> 3 using namespace std; 4 class S { 5 public: 6 S(int a0) { cout << a0 << endl; } 7 S(double a0, int b0) : d(a0), b(b0){ cout << a0 << b0 << endl; } 8 S(char *p0) : d(a), b(2) { cout << p << endl;} 9 S(int &a0) : a(0), b(1), c("abc"), d(r), p(new int) { } 10 private: 11 int a; 12 const int b; 13 string c; 14 int &d; 15 int *p; 16 }; 17 int main() { 18 S a(1); 19 S b; 20 S c(0.0, 1); 21 S d("hello"); 22 S e(true); 23 S f(a); 24 e = a; 25 }
1 #include <string> 2 #include <iostream> 3 using namespace std; 4 class Person{ 5 public: 6 Person(string name) : name_ (name) { } 7 virtual void print() const = 0 { cout << name_; } 8 virtual bool compare(Person p) const { return p.name_ == name_; } 9 protected: 10 string name_; 11 }; 12 class Student : public Person { 13 Student(string name, string id) { name_ = name; id_ = id; } 14 Student(Person p, string id) { name_ = p.name_; id_ = id;} 15 bool compare(Student s) const { return s.name_==name_ && s.id_ == id_; } 16 void print() { cout << name_ << id_ << endl; } 17 private: 18 string id_; 19 }; 20 21 int main() { 22 Person p("Mike"); 23 Student s("jack", "12345"); 24 Student t(p, "23424"); 25 cout << s.compare(t); 26 cout << p.compare(t); 27 cout << s.compare(p); 28 s.print(); 29 s.Person::print(); 30 }
1 class Integer{ 2 public: 3 Integer(int a = 0) : i(a) {} 4 Integer operator+(int a, int b) { return a + b;} 5 Integer operator-() { return -i; } 6 Integer operator+() { return i; } 7 Integer operator++() { return ++i; } 8 Integer operator++(int) { return i++; } 9 bool operator<>(int a) { return i != a; } 10 private: 11 int i; 12 }; 13 void operator>>(ostream &os, Integer i) { 14 os << i; 15 } 16 istream & operator<<(istream &is, Integer i) { 17 is >> i.i; 18 return is; 19 } 20 Integer operator-(Integer a, Integer b) { 21 return a.i - b.i; 22 } 23 int main() { 24 Integer i(-1); 25 Integer j; 26 cin >> j; 27 i = -i; 28 i = i - j; 29 i = i + 10; 30 cout << i; 31 }
读程序，写出程序运行的结果
1 #include <iostream> 2 #include <string> 3 using namespace std; 4 int f( string a ); 5 int f( int b , int c = 1); 6 int f( bool b); 7 int main() { 8 string s = ""; 9 cout << f(s) << endl; 10 cout << f('\060') << endl; 11 cout << f(1, 2) << endl; 12 cout << f(false) << endl; 13 cout << f(0) << endl; 14 } 15 int f( string a) { 16 return a.length(); 17 } 18 int f( int b, int c) { 19 return b * c + b + c + 1; 20 } 21 int f(bool b) { 22 return b?1:-1; 23 }
1 #include <iostream> 2 using namespace std; 3 class Z { 4 public: 5 Z(int i) : id(i) { cout << id << " created" << endl; } 6 ~Z() { cout << id << " destroyed" << endl; } 7 Z(Z &z) : id(z.id) { cout << id << " created a copy" << endl; } 8 private: 9 int id; 10 }; 11 Z z(0); 12 int main() { 13 cout << "main start" << endl; 14 Z z1(1); 15 Z z2(2); 16 Z *z3 = new Z(3); 17 Z z4(z1); 18 }
1 #include <iostream> 2 using namespace std; 3 class X { 4 public: 5 X(int a) : x(a) { cout << "create X:" << x << endl; } 6 ~X() { cout << "destroy X:"<< x << endl; } 7 private: 8 int x; 9 }; 10 class Y : public X{ 11 public: 12 Y() : x(1), X(2) { cout << "create Y" << endl; } 13 ~Y() { cout << "destroy Y" << endl; } 14 private: 15 X x; 16 }; 17 18 int main() { 19 X x(5); 20 Y y; 21 }
1 #include <iostream> 2 using namespace std; 3 class B{ 4 public: 5 virtual void f() { cout << "B::f() "; } 6 void g() { cout << "B::g() "; } 7 virtual void h() { f(); } 8 }; 9 class D : public B { 10 public: 11 void f() { cout << "D::f() "; } 12 void g() { cout << "D::g() "; } 13 }; 14 int main() { 15 B b; 16 b.f(); b.g(); b.h(); 17 cout << endl; 18 B *p = &b; 19 p->f(); p->g(); p->h(); 20 cout << endl; 21 B *p = new D; 22 p->f(); p->g(); p->h(); 23 cout << endl; 24 B &r = *p; 25 r.f(); r.g(); r.h(); 26 cout << endl; 27 delete p; 28 }
1 #include <iostream> 2 using namespace std; 3 class B{ 4 public: 5 B () { cout << "create B" << endl; } 6 virtual ~B() { cout << "destroy B" << endl; } 7 virtual void f() { cout << "B::f()" << endl; } 8 virtual void f(int a) { cout << "B::f(int)" << endl; } 9 }; 10 class D : public B { 11 public: 12 D() { cout << "create D" << endl; } 13 virtual ~D() { cout << "destroy D" << endl; } 14 virtual void f() { cout << "D::f()" << endl; } 15 virtual void f(bool a) { cout << "D::f(bool)" << endl; } 16 }; 17 int main() { 18 B *p = new B; 19 p->f(); 20 p->f(0); 21 delete p; 22 p = new D; 23 p->f(); 24 p->f(0); 25 delete p; 26 D *d = new D; 27 d->f(); 28 d->f(0); 29 delete d; 30 }
1 #include <iostream> 2 using namespace std; 3 class D { 4 public: 5 D() { cout << "D created" << endl; } 6 D(D&) { cout << "D created a copy" << endl; } 7 ~D() { cout << "D destroyed" << endl; } 8 D& operator=(D&) { cout << "D assigned" << endl; return *this; } 9 void operator++() { cout << "operator++" << endl; } 10 void operator++(int) { cout << "operator++ with int" << endl; } 11 }; 12 int main() { 13 D d1; 14 D d2(d1); 15 d1 = d2; 16 ++d1; 17 d2++; 18 }
程序填空题
编程题，按要求编写程序
实现字符串类string，声明如下
1 class string { 2 public: 3 string(const char *str = ""); // 普通构造函数 4 string(const string &other); // 拷贝构造函数 5 ~string(); // 析构函数 6 string & operator = (const string &other); // 赋值函数 7 bool operator==(const string &s); 8 bool operator!=(const string &s); 9 bool operator<(const string &s); 10 bool operator>(const string &s); 11 bool operator<=(const string &s); 12 bool operator>=(const string &s); 13 string operator +(const string &s); //连接 14 string operator +=(const string &s); 15 int length() const; 16 bool empty() const; 17 char* c_str() { return m_data; } 18 private: 19 char *m_data; // 用于保存字符串 20 }; 21 ostream &operator<<(ostream &os, const string &s); 22 istream &operator>>(istream &is, string &s);
实现完整的复数运算，复数类的声明如下：
1 class complex { 2 public: 3 complex(double r = 0.0, double i= 0.0); 4 complex operator+(); 5 complex operator-(); 6 complex operator+=(complex); 7 complex operator-=(complex); 8 complex operator*=(complex); 9 bool operator!(); //非0返回假，0返回真 10 double abs(); //取模 11 double arg(); //取角度 12 complex conj(); //共轭 13 double &real(); //实部 14 double &imag(); //虚部 15 private: 16 double real_, imag_; 17 }; 18 ostream &operator<<(ostream &os, complex); 19 istream &operator>>(istream &is, complex &); 20 complex operator+(complex a, complex b); 21 complex operator*(complex a, complex b); 22 complex operator-(complex a, complex b); 23 complex operator==(complex a, complex b); 24 complex operator!=(complex a, complex b);
实现Stack类，提供push（把一个元素放入栈中），pop（把栈中最后一个元素删去），top（取栈中最后一个元素）。请实现Stack类，使其能够得到正确的运行结果。
1 #include <iostream> 2 using namespace std; 3 int main() { 4 Stack s1(5); 5 for(int i = 0; i < 3; i++) s1.push(i); 6 Stack s2(s1); 7 while(s1.size() > 0) { 8 cout << s1.top() << endl; 9 s1.pop(); 10 } 11 s1 = s2; 12 for(int i = 3; i < 5; i++) s1.push(i); 13 while(s1.size() > 0) { 14 cout << s1.top() << endl; 15 s1.pop(); 16 } 17 }
实现队列Queue类，提供enqueue（把一个元素放在队列的末尾中），dequeue（把队列中第一个元素删去），front（取队列中第一个元素的值），back（取队列最后一个元素的值）。请实现Queue类，使其能够得到正确的运行结果。
1 #include <iostream> 2 using namespace std; 3 int main() { 4 Queue s1(5); 5 for(int i = 0; i < 3; i++) s1.enqueue(i); 6 Queue s2(s1); 7 while(s1.size() > 0) { 8 cout << s1.front() << endl; 9 s1.dequeue(); 10 } 11 s1 = s2; 12 for(int i = 3; i < 5; i++) s1.enqueue(i); 13 while(s1.size() > 0) { 14 cout << s1.front() << endl; 15 s1.dequeue(); 16 } 17 }
财务软件。Account为账户，AccountList为账户的集合，两个类的声明如下，请给出这两个类的实现。
1 class Account { 2 public: 3 Account(string name, int type, double amount); 4 string &name(); 5 int &type(); 6 double &amount(); 7 private: 8 string name_; 9 int type_; 10 double amount_; 11 }; 12 class AccountList { 13 public: 14 AccountList(int capacity); 15 void AddAccount(Account account); 16 void RemoveAccount(string name); 17 int Find(string name); 18 Account &At(int i); 19 private: 20 int capacity_; 21 int size_; 22 Account *accounts; 23 };
学校的人事关系。学校里面有四类人：人（Person），学生（Student），教师（Teacher），助教（Assistant）。其中助教是一类特殊的人，他们是教师，同时也是学生。请完成以下程序，使之能得到正确运行结果。
1 #include <iostream> 2 #include <string> 3 using namespace std; 4 int main() { 5 Person *p[4]; 6 p[0] = new Person("jack"); 7 p[1] = new Student("rose", "12345"); 8 p[2] = new Teacher("czk", "lecturer"); 9 p[3] = new Assistant("oldbig", "23456", "assistant"); 10 for(int i= 0; i < 4; i++) { 11 p[i] -> print(); 12 cout << endl; 13 } 14 }
声明一个Shape抽象类，在此基础上派生出Rectangle类（矩形）和Circle类（圆），二者都有GetArea()函数计算对象的面积，请按下面的要求给出Shape类、Rectangle类、Circle类的实现：Rectangle类有Width宽度，Height高度属性；Circle类有Radius半径属性；Rectangle类和Circle类的构造函数用以初始化上述参数；每个类都有GetArea函数，用以计算此形状的面积；主函数（如下）已经写好，对Rectangle、Circle类进行测试，使它们以统一的操作界面输出面积。
1 #include <iostream> 2 using namespace std; 3 int main() 4 { 5 Shape *shapes[5]; 6 shape[0] = new Rectangle(1.0, 2.0); 7 shape[1] = new Circle(5.0); 8 shape[2] = new Circle(1.0); 9 shape[3] = new Rectange(3.0, 1.5); 10 shape[4] = new Circle(0.0); 11 for( int i = 0; i < 5; i++) 12 cout<<"Area of shape "<<i <<" is "<<shape[i]->GetArea()<<endl; 13 }