这个该怎么做啊，求解答

代码如下，如有帮助，请帮忙采纳一下，谢谢。

#include <iostream>
#include <string>
using namespace std;

struct Student 
{
    int id;
    string name;
    int score[3];
    float avg;
};

void input(struct Student st[],int n)
{
    int i;
    for (i=0;i<n;i++)
    {
        cout << "请输入学生"<<i+1<<"的学号、姓名、三门课成绩:";
        cin >> st[i].id >> st[i].name >> st[i].score[0] >> st[i].score[1] >> st[i].score[2] ;
    }
}

void average1(struct Student st[],int n)
{
    for (int i = 0;i<n;i++)
    {
        st[i].avg = (st[i].score[0] + st[i].score[1]+st[i].score[2])/3.0;
    }
}

void average2(struct Student st[],int n,float avg[])
{
    for (int i = 0;i<3;i++)
    {
        avg[i] = 0;
        for (int j = 0;j<n;j++)
        {
            avg[i] += st[j].score[i];
        }
        avg[i] = avg[i]/n;
    }
}

void sort(struct Student st[],int n)
{
    struct Student tt;
    for (int i = 0;i<n-1;i++)
    {
        for (int j=0;j<n-1-i;j++)
        {
            if (st[j].avg > st[j+1].avg)
            {
                tt = st[j];
                st[j] = st[j+1];
                st[j+1] = tt;
            }
        }
    }
    
}

void output(struct Student st[],int n,float avg[])
{
    //显示每门课的成绩
    cout << "学生成绩："<< endl;
    for (int i = 0;i<n;i++)
    {
        cout << st[i].score[0] <<"  "<< st[i].score[1] << "  " << st[i].score[2] << "  " << st[i].avg <<endl;
    }
    cout << "每门课的平均分：";
    cout << avg[0] << "  " << avg[1] << "  " << avg[2] <<endl;
}

int main()
{
    struct Student st[10];
    float avg[3];
    input(st,10);
    average1(st,10);
    average2(st,10,avg);
    sort(st,10);
    output(st,10,avg);
    return 0;
}