如何在c++中对二维数组进行排序

我有5个学生的名字和他们3门课的成绩，我已经计算出他们3门课的平均分。然后我需要根据他们的数据(姓名，三门课程的成绩和平均成绩)从平均成绩最高的到最低的对他们进行排序。有人能告诉我我的代码有什么问题吗?这是我的代码…

# include <iostream>
# include <string>
# include <iomanip>
using namespace std;
void read(string names[],double grades[][4],int n);
void average(double grades[][4], int n);
void sort(string names[],double grades[][4], int n);
int main()
{
    string names[5]; double grades[5][4];
    cout<<fixed<<showpoint<<setprecision (2);
    cout<<" please enter the names and grades(math,phy,cpp) for 5 studentsn";
    read(names,grades,5);
    average(grades,5);
    sort(names,grades,5);
    for(int rows=0; rows<5; rows++)
    {
        cout<<names[rows]<<"t";
        for( int col=0; col<4; col++)
        {
            cout<<grades[rows][col]<<"t";
        }
        cout<<endl;
    }



    system("pause");
    return 0;
}
void read(string names[],double grades[][4],int n)
{
    for(int rows=0; rows<n; rows++)
    {
            cin>>names[rows];
        for( int col=0; col<3; col++)
        { 
            cin>>grades[rows][col];
        }
    }
    system("cls");
}
void average(double grades[][4], int n)
{
    double sum;
    for(int rows=0; rows<n; rows++)
    {
        sum=0.0;
        for(int col=0; col<3;col++)
        {
            sum=sum+grades[rows][col];
        }
        grades[rows][3]=sum/3;
    }
}
void sort(string names[],double grades[][4], int n)
{
    double temp;int end=n;string swap_names;

    for(int rows=0; rows<end; rows++)
    {
        if(grades[rows][3]> grades[rows+1][3])
        {
            for(int col=0; col<4;col++)
            {
                temp=grades[rows+1][col];
                grades[rows+1][col]=grades[rows][col];
                grades[rows][col]=temp;
            }
            swap_names=names[rows+1];
            names[rows+1]=names[rows];
            names[rows]=swap_names;
        }
    }

}

谢谢。