3.动态存储管理和程序调试

point.h

----------------------------------------------------------------------------

#include<iostream>

#include<cmath>

using namespace std;

class point{

private:
double x,y;

public:
point(double =0,double =0);
double Getx();             //获取x
double Gety();             //获取y
void setxy(double,double); //设置x,y
~point();                  //析构的同时显示删去的点

};

void set(point *);             //设置x,y

void Display(point *);         //显示x,y

double lenth(point *);         //计算折现长度

const int num=10;              //设置开辟内存的大小

--------------------------------------------------------------------------

#include"point.h"

point::point(double a,double b){
x=a;
y=b;

}

double point::Getx(){
return x;

}

double point::Gety(){
return y;

}

void point::setxy(double a,double b){
x=a;
y=b;

}

point::~point(){
cout<<x<<"，"<<y<<"is delete."<<endl;

}

void set(point *p){
double a,b;
int i;
for(i=0;i<num;i++)
{
cout<<"请输入第"<<i<<"个点坐标：";
cin>>a>>b;
(p+i)->setxy(a,b);
}

}

void Display(point *p){
for(int i=0;i<num;i++)
{
cout<<"第"<<i<<"个点的坐标是："<<(p+i)->Getx()<<"，"<<(p+i)->Gety()<<endl;
}

}

double lenth(point *p){
double sum=0.0,a1,a2,b1,b2;
a1=p->Getx();
b1=p->Gety();
for(int i=1;i<num;i++)
{
a2=(p+i)->Getx();
b2=(p+i)->Gety();
sum+=sqrt((a2-a1)*(a2-a1)+(b2-b1)*(b2-b1));
a1=a2;
b1=b2;
}
return sum;

}

int main()

{
point *p=new point[10];
if(p==NULL)
{
cout<<"分配内存失败。"<<endl;
return 0;
}
set(p);
Display(p);
cout<<"lenth="<<lenth(p)<<endl;
delete []p;
return 0;

}