sort an array

//
//  main.cpp
//  teststrcmp
//
//  Created by Rizky Herucakra on 6/13/13.
//  Copyright (c) 2013 Rizky Herucakra. All rights reserved.

#include <iostream>
#include <string>

using namespace std;

struct student
{
    char name[50];
    float q1, q2, q3;
    float ave;
};


void swap(float* a, float* b){
    float tmp;
    tmp = *a;
    *a = *b;
    *b = tmp;
}


void swap(char* a, char* b){
    char buff[50];
    strcpy(buff,a);
    strcpy(a,b);
    strcpy(b,buff);
}

void swap(student* a, student* b)
{
    swap(&(a->q1),&(b->q1) );
    swap(&(a->q2),&(b->q2) );
    swap(&(a->q3),&(b->q3) );
    swap(&(a->ave),&(b->ave) );
    swap(a->name,b->name );
}

void my_sort(student* s,int num_item){

    int n = num_item;

    do{
        int newn = 0;
        for (int i = 1; i <= n - 1; ++i ){
            if (strcmp(s[i -1 ].name,s[i].name ) >= 0 ){
                swap(&s[i -1 ],&s[i]);
                newn = i;
            }
        }
        n = newn;

    }while (n != 0);
}

int main()
{
    student x[50];
    int i, j, k;
    char xtemp[50];

    for (i=0; i!=3; i++)
    {
        cout << "\n\n\tPlease enter a Student Name: ";
        cin >> x[i].name;

        cout << "\n\tPlease enter his/her score for QUIZ1: ";
        cin >> x[i].q1;

        cout << "\n\tPlease enter his/her score for QUIZ2: ";
        cin >> x[i].q2;

        cout << "\n\tPlease enter his/her score for QUIZ3: ";
        cin >> x[i].q3;

        x[i].ave = (x[i].q1+x[i].q2+x[i].q3) / 3;

        cout<<"\n\t-----------------------------------";
    }

    my_sort(x,3);

    // display

    cout << "\n\n\n\tNAME\t\tQUIZ1\t\t\QUIZ2\t\tQUIZ3\t\tAVE"<<endl;



    for (i=0; i!=3; i++)
    {
        cout << "\n\t"<<x[i].name;
        cout <<"\t\t"<<x[i].q1;
        cout <<"\t\t"<<x[i].q2;
        cout <<"\t\t"<<x[i].q3;
        cout <<"\t\t"<<x[i].ave<<endl;
    }


    cin.get();
    return 0;
}