Сортировка массива структур

#include "stdafx.h"
using namespace std;
 
const int num = 5;
 
struct Student  {
    string name;
    int groupNumber;
    int progress[num];
};

#include "stdafx.h"
#include "Student.h"
using namespace std;
 
int _tmain(int argc, _TCHAR* argv[])
{
srand((unsigned)time(NULL));
 
int n;
cout << "Input n = ";
cin >> n;
cin.ignore();
 
Student * Group = new Student[n];
 
for (int i = 0; i < n; ++i)
{
    cout << "Input name: ";
    getline (cin, Group[i].name);
    Group[i].groupNumber = rand()%5 + 1;
    for (int j = 0; j < num; ++j)
    {
        Group[i].progress[j] = rand()%5 + 2;
    }
}
 
int * groupNumberArray = new int[n];
for (int i = 0; i < n; ++i)
{
    groupNumberArray[i] = Group[i].groupNumber;
}
 
for (int i; i < n - 1; ++i)
{
    int min = i;
    for (int j = i + 1; j < n; ++j)
    {
        if (groupNumberArray[min] <= groupNumberArray[j]) continue;
        min = j;
    }
    if (min != i)
    {
        int temp = groupNumberArray[i];
        groupNumberArray[i] = groupNumberArray[min];
        groupNumberArray[min] = temp;
 
        Student * tempStudent = &Group[i];
        &Group[min] = &Group[i];
        &Group[i] = tempStudent;
    }
}
 
cout << "\n\n";
 
delete [] Group;
delete [] groupNumberArray;
 
system("PAUSE");
return 0;
}

 Student temp;
    for(int i=0;i<size;i++){            
        for(int j=size-1;j>i;j--){    
            if(arr[j-1].groupNumber<arr[j].groupNumber){
                temp=arr[j-1];
                arr[j-1]=arr[j];
                arr[j]=temp;
            }
        }
    }