C面向对象程序设计教程第版陈维兴林小茶课后习题答案及解析

4.16

4 4.17 (1,2) 5,6 (6,9) 4.18

class base1 class base2 class level2 class base2 class level1 class toplevel 4.19

#include using namespace std; #include

class table {

public:

table(int p, int q) {

i = p; j = q;

}

void ascii(void); protected: int i, j; };

void table::ascii() {

int k = 1;

for(; i <= j; i++) {

cout << setw(4) << i << \ \ << (char)i; if((k) == 0) {

cout << \; } k++; }

cout << \; }

class der_table:public table {

public:

der_table(int p, int q, char *m):table(p,q) {

c = m; }

void print(); protected: char *c; };

void der_table::print() {

cout << c <<\; table::ascii(); }

int main() {

der_table ob('a', 'z', \); ob.print(); return 0; }

4.20

#include using namespace std; #include

class area_c1 {

protected:

double height; double width; public:

area_c1(double r, double s) {

height = r; width = s; }

virtual double area() = 0; };

class rectangle : public area_c1 {

public:

rectangle(double r, double s):area_c1(r, s){} virtual double area(); };

double rectangle::area() {

return height * width; }

class isosceles : public area_c1 {

public:

isosceles(double r, double s):area_c1(r, s){} virtual double area(); };

double isosceles::area() {

return (height * width)/2;

}

int main() {

rectangle r(10, 5); isosceles i(4, 6); area_c1 *a; a = &r;

cout<< \矩形的面积是：\ << a->area() << endl; a = &i;

cout << \三角形的面积是：\ << a->area() <

#include using namespace std; #include

class Time {

public:

Time(int h, int m, int s) {

hours = h; minutes = m; seconds = s; }

void display() {

cout << \出生时间：\ << hours << \时\ << minutes << \分\ << seconds << \秒\ << endl; }

protected:

int hours, minutes, seconds; };

class Date {

public: