Returning array not working...

[thebolt]

With this code I am working on manipulating numbers in an array and passing them through functions.

I am using a bubble sort to pick out the highest and lowest numbers in the array. I then want to output the original order that I typed the numbers into the array before they were sorted from highest to lowest and lowest to highest. How do I achieve this? I tried passing just one variable in the array but this resulted in my program simply outputting "0" for highest and lowest number.

If you don't understand my question I will be happy to clarify.

I am also aware my averages aren't working. That will be fixed later.

#include "stdafx.h"
#include <iostream>
using namespace std;

void getGrades (int arr[], int y)
{       
        int j = 1;
        for (int i = 0; i <= 4; i++)
    {
        cout << "Enter grade " << j << ": ";
        cin >> arr[i];
        j = j + 1;
    }
}
//******************************************************************************************************************
int highestGrade(int arr[], int y)
{   
    for (int i = 0; i <= 3; i++)
    {
        for (int j = i + 1; j <= 4; j++)
        {
            if (arr[j] > arr[i])
            {
                int temp = arr[i];
                arr[i] = arr[j];
                arr[j] = temp;
            }
        }
    }
    return arr [0];
}
//******************************************************************************************************************
int lowestGrade(int arr[], int y)
{
    for (int i = 0; i <= 3; i++)
    {
        for (int j = i + 1; j <= 4; j++)
        {
            if (arr[j] < arr[i])
            {
                int temp = arr[i];
                arr[i] = arr[j];
                arr[j] = temp;
            }
        }

    }
    return arr [0];
}
//******************************************************************************************************************
int averageGrade(int arr[], int y)
{
    y = 0;
    for (int i = 0; i <= 4; i++)
    {
        y = y + arr[i];
    }
    return y;
}
//******************************************************************************************************************
void showGrades(int arr[], int y)
{
	y = 1;
	for (int i = 0; i <= 4; i++)
	{
		cout << "Grade " << y << ": " << arr [i] << endl;
		y++;
	}
}
//******************************************************************************************************************
void main()
{   
    int grades[5];
    int elements = 5;

    getGrades(grades, elements);
    cout << endl << endl;

    highestGrade(grades, elements);
    cout << "Highest grade: " << grades [0] << endl << endl;

    lowestGrade(grades, elements);
    cout << "Lowest grade : " << grades [0] << endl << endl;

    averageGrade(grades, elements);
    cout << "Average grade: " << elements << endl << endl;

	showGrades(grades, elements);

    cout << endl << endl;
    system("pause");
}

[jsmith]

Bubblesort is way overkill to find the highest and/or lowest values in an array.
Bubblesort runs in O(n^2) time whereas finding the highest and/or lowest value should run in linear time.

One way to accomplish what you want is to use the standard algorithms:

#include <algorithm>

template< typename T, size_t N >
T highestGrade( T (&array)[ N ] )
{ return *std::max_element( array, array + N ); }

Or if you're unfamiliar with templates

int highestGrade( int array[], size_t numElems )
{ return *std::max_element( array, array + numElems ); }

And if you need to write the loop yourself, then here's one way to do it:

int highestGrade( int array[], size_t numElems )
{
    int highest = array[ 0 ];   // Assumes numElems > 0
    for( size_t i = 1; i < numElems; ++i )
        if( array[ i ] > highest )
            highest = array[ i ];

    return highest;
}

Note that all of the above functions avoid the problem of having your grade list
change as a result of the bubblesort.

Still another alternative is to make a copy of the array and pass the copy to highestGrade() and lowestGrade():

int main() {
    int grades[ 5 ];
    int gradeCopy[ 5 ];
    size_t elements = 5;

    getGrades( grades, elements );
    memcpy( gradeCopy, grades, sizeof( grades ) );
    // Or std::copy( grades, grades + 5, gradeCopy );
    
    // ...
}