need urgent help with vector

[MarzenaM]

I have to write programm to sort numbers from in ascending order, using vector (C++ language)
I did this using array, and it works perfect. Please could you help me replace array to vector. It's very urgent. :'( My code is:

#include <iostream>
void fill_array(int a[], int size, int& number_used);
void sort(int a[], int number_used);
void swap_values(int& v1, int& v2);
int index_of_smallest(const int a[], int start_index, int number_used);
int main( )
{
    using namespace std;
    cout << "This program sorts numbers from lowest to highest.\n";
    int sample_array[10], number_used;
    fill_array(sample_array, 10, number_used);
    sort(sample_array, number_used);
    cout << "In sorted order the numbers are:\n";
    for (int index = 0; index < number_used; index++)
        cout << sample_array[index] << " ";
    cout << endl;
    return 0;
}
void fill_array(int a[], int size, int& number_used)
{
    using namespace std;
    cout << "Enter up to " << size << " nonnegative whole numbers.\n"
         << "Mark the end of the list with a negative number.\n";
    int next, index = 0;
    cin >> next;
    while ((next >= 0) && (index < size))
    {
        a[index] = next;
        index++;
        cin >> next;
    }
    number_used = index;
}
void sort(int a[], int number_used)
{
    int index_of_next_smallest;
    for (int index = 0; index < number_used - 1; index++)
    {
        index_of_next_smallest =
                     index_of_smallest(a, index, number_used);
        swap_values(a[index], a[index_of_next_smallest]);
      }
}
void swap_values(int& v1, int& v2)
{
    int temp;
    temp = v1;
    v1 = v2;
    v2 = temp;
}
int index_of_smallest(const int a[], int start_index, int number_used)
{
    int min = a[start_index],
        index_of_min = start_index;
    for (int index = start_index + 1; index < number_used; index++)
        if (a[index] < min)
        {
            min = a[index];
            index_of_min = index;
         }
    return index_of_min;
}

[Ancient Dragon]

c++ has a sort() function, all you have to write is a comparison function. Here is a short tutorial

If you want to keep all the code you have already written, just replace the array with a vector, then call the vector's resize() method to initialize it to contain 10 elements. I think the rest of the program should work without change.

[MarzenaM]

I can't use classes and structures, we didn't do it yet.
And I can't just replace array with vector because since vector can dermine the number used with the member function size the function will not need a parameter like numberr_used.
Any other ideas???? I am really desperate. :S

[Ancient Dragon]

you sait you have to use vector, just replace the array with a vector as mentioned before. If you don't want number_used then delete it from the program. Give it a try and repost your most recent attempt at solving the problem.

vector<int> sample_array;
sample_array.resize(10);

[Lerner]

You could always try this syntax:

vector sample_array(10);

if you want a vector of ints with space for exactly 10 ints and don't want to call resize().

If you find that the stuff you do in fill() and sort() aren't maintained in the vector in the calling function, then you will need to pass the vector by reference explicitly instead of the automatic pass by reference that happens when you pass arrays.

Oh, and to use the STL vector class you'll need to include the vector header file; and I'd move the using namespace std; line to have global scope rather than function scope so you don't have to type it twice (or more often).