c++编程(学生平均成绩)

Question

设计一个类来计算某个学生3门课的平均值,对学生的描述除了成绩之外,还有学生的姓名,编程显示5个学生的姓名和平均成绩,及总平均值,要求用到构造函数?

Answer 1

#include <iostream.h>
#include <string.h>
class student
{
char *name;
float kk[3],total;
public:
student();
student(char *n,float *k);
~student();
void show();
void set(char *n,float *k);
float pingjun();
};
void student::set(char *n,float *k)
{
total=0.;
name =new char[strlen(n)+1];
strcpy(name,n);
for(int i=0;i<3;i++)
kk[i] = k[i];
}
student::student()
{
total=0.;
name= new char[5];
strcpy(name,"noname");
for(int i=0;i<3;i++)
kk[i] = 0.;
}
student::student(char *n,float *k)
{
total=0.;
name =new char[strlen(n)+1];
strcpy(name,n);
for(int i=0;i<3;i++)
kk[i] = k[i];
}
student::~student()
{
delete name;
for(int i=0;i<3;i++)
kk[i] = 0.;
}
float student::pingjun()
{
for(int i=0;i<3;i++)
total+=kk[i];
return total/3.0;
}
void student::show()
{
cout<<name<<"同学的成绩如下:"<<endl;
for(int i=0;i<3;i++)
{
cout<<kk[i]<<" ";
}
cout<<"该同学的均分为:"<<pingjun()<<endl;
}
void main()
{
float t;
char name[5][10]={"张三","李四","王五","赵六","神"};
float kk[5][3]={{22,33,44},{33,44,55},{44,55,66},{55,66,77},{66,77,88}};
for(int i=0;i<5;i++)
{
student a(name[i],kk[i]);
a.show();
}
for(i=0;i<3;i++)
{
t=0.;
for(int j=0;j<5;j++)
t+=kk[j][i];
cout<<"第"<<i+1<<"门总平均成绩为:"<<t/5.0<<endl;
}
}