编写一个程序，已有若干学生的数据，包括学号，姓名，成绩，要求输出这些学生的数据并计算出学生人数和平均成绩



#include<iostream> 
#include<string> 
using namespace std; 
class  student 
{ 
public: 
 void show() 
{ 
  cout<<"num="<<num<<endl; 
     cout<<"name="<<name<<endl; 
    cout<<"score="<<score<<endl; 
  } 
 static void show1() 
 { 
   cout<<"the numbers of students:"<<count<<endl; 
  cout<<"the aver score of students:"<<aver<<endl; 
 } 
 student(string num1,string name1,double score1) 
 { 
   num=num1; 
  name=name1; 
 score=score1; 
   count++; 
  sum+=score1; 
  aver=sum/count; 
    } 
private: 
 string num; 
 string name; 
 double score; 
  static double sum; 
 static int count; 
   static double aver; 
}; 
double student::sum=0.0; 
int student::count=0; 
double  student::aver=0.0; 
int main() 
{ 
   student stu1("14","小红",78);       
   stu1.show(); 
   student stu2("24","小蓝",90); 
       stu2.show(); 
    student stu3("25","小敏",85); 
       stu3.show(); 
   student::show1(); 
   return 0; 
}