自考C++试题与答案(9套合集)-3-4.

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四、完成程序题(本大题共5小题，每小题4分，共20分)

1. 在下面程序横线处填上适当内容，使程序执行结果为：\。

#include #include using namespace std; class mystring {public:

char * pdata; mystring(int len)

{pdata=new char［len+1］; }

~mystring() {delete pdata;}

void show(){cout<

void fun(mystring** array,int len) {mystring*old=*array;

_*array=new mystring(len)______; memcpy(*array, old, len); }

void main()

{mystring str(20); mystring*pstr=&str; mystring**ppstr=&pstr;

strcpy(str.pdata,\fun(ppstr, 20); str.show();_______ }

2. 在下面程序横线处填上适当字句，完成类的定义。

class line; class box { private: int color; int upx, upy; int lowx, lowy; public:

friend int same_color(line l, box b); void set_color (int c){color=c;}

void define_box (int x1, int y1, int x2, int y2) {upx=x1;upy=y1;lowx=x2;lowy=y2;} };

class line { private:

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int color;

int startx, starty; int endx, endy; public:

friend int same_color(line l,box b); void set_color (int c) {color=c;}

void define_line (int x1,int y1,int x2,int y2) {startx=x1;starty=y1;endx=x2;endy=y2;} };

int same_color(line l, box b) {if (l.color==b.color) return 1; return 0; }

3. 下面程序用来求直角三角形斜边长度。

#include #include class Point {private: double x,y;

friend Line;__________ public:

Point(double i=0,double j=0) {x=i;y=j;}

Point(Point &p) {x=p.x;y=p.y;} };

class Line {private: Point p1,p2; public:

Line(Point &xp1,Point &xp2):p1(xp1),p2(xp2)________{} double GetLength(); };

double Line::GetLength() {double dx=p2.x