作业4.21

#include <iostream>#include <string>using namespace std;class student{private:int number;string name;float score;static int sum;static float total;static float average;public:student(int number1,string name1,float score1);void show();static void show_sum_ave();};student::student(int number1,string name1,float score1){number=number1;name=name1;score=score1;++sum;total=total+score;average=total/sum;}void student::show(){cout<<"学号："<<number<<"姓名"<<name<<"分数"<<score<<endl;}void student::show_sum_ave(){cout<<"学生总人数："<<sum<<endl;cout<<"平均成绩："<<average<<endl;cout<<"总成绩："<<total<<endl;}int student::sum=0;float student::average=0.0;float student::total=0.0;int main(){student s1(1,"linminyi",87);s1.show();student s2(2,"zhuangzihui",88);s2.show();student s3(3,"zhaoqiqini",89);s3.show();s3.show_sum_ave();return 0;}