Merge Sort

#include <iostream>
#include <string>

void DoMerge(int numbers[], int left, int mid, int right)
{
    int temp[25];
    int i, left_end, num_elements, tmp_pos;

    left_end = (mid - 1);
    tmp_pos = left;
    num_elements = (right - left + 1);

    while ((left <= left_end) && (mid <= right))
    {
        if (numbers[left] <= numbers[mid])
            temp[tmp_pos++] = numbers[left++];
        else
            temp[tmp_pos++] = numbers[mid++];
    }
    while (left <= left_end)
        temp[tmp_pos++] = numbers[left++];

    while (mid <= right)
        temp[tmp_pos++] = numbers[mid++];
    for (i=0; i < num_elements; i++)
        numbers[right--] = temp[right];

}

void MergeSort(int numbers[], int left, int right)
{
  int mid;

  if (right > left)
  {
    mid = (right + left) / 2;
    MergeSort(numbers, left, mid);
    MergeSort(numbers, (mid+1), right);
    DoMerge(numbers, left, (mid+1), right);
  }
}

void MergeSortHelper(int numbers[], int array_size)
{
    MergeSort(numbers, 0, array_size - 1);
}

void max()
{
    int max;
    std::cout << "\nProgram for Ascending order of Numeric Values using MERGE SORT";
    std::cout << "\n\nEnter the total number of elements: ";
    std::cin >> max;

    int *numarray = new int[max];

    for(int i = 0; i < max; i++)
    {
        std::cout << "\nEnter [" << i + 1 << "] element: ";
        std::cin >> numarray[i];
    }

    std::cout << "Before Sorting   : ";
    for(int k = 0; k < max; k++)
        std::cout << numarray[k] << " ";
    std::cout << "\n";

    MergeSortHelper(numarray,max);
    std::cout << "\n\nThe numbers in ascending orders are given below:\n\n";
    for(int i = 0; i < max; i++)
    {
        std::cout << "Sorted [" << i + 1 << "] element: ";
        std::cout << numarray[i];
        std::cout << "\n";
    }

    delete [] numarray;
 

  }