用C语言进行合并排序和删除重复项(任何语言都可以)

这是我的第一个问题，所以如果我遗漏了什么或对某个项目有歧义，我提前道歉。

无论如何，这是我从GeeksForGeeks.org获得的代码(为问题的目的修改数组)，但概念是相同的:我如何需要修改提供的合并排序代码，以便在排序时删除重复项。我想我可以改变:

if (L[i] <= R[j])
{
    arr[k] = L[i];
    i++;
}
else
{
    arr[k] = R[j];
    j++;
}
k++;

if (L[i] < R[j])
{
    arr[k] = L[i];
    i++;
}
else if (L[i] > R[j])
{
    arr[k] = R[j];
    j++;
}
else
{
    arr[k] = L[i];
    i++;
    j++;
}
k++;

但是它脱离了排序的数组。是的，它们必须在排序时删除，而不是在其他步骤中删除。下面是承诺的代码:

int shift = 0;
int merge(int arr[], int l, int m, int r)
{
int i, j, k;
int n1 = m - l + 1;
int n2 =  r - m;
/* create temp arrays */
int L[n1], R[n2];
/* Copy data to temp arrays L[] and R[] */
for (i = 0; i < n1; i++)
    L[i] = arr[l + i];
for (j = 0; j < n2; j++)
    R[j] = arr[m + 1+ j];
/* Merge the temp arrays back into arr[l..r]*/
i = 0; // Initial index of first subarray
j = 0; // Initial index of second subarray
k = l; // Initial index of merged subarray
while (i < n1 && j < n2)
{
    if (L[i] <  R[j])
    {
        arr[k] = L[i];
        i++;
    }
    else if (L[i] >  R[j])
    {
        arr[k] = R[j];
        j++;
    }
    else
    {
        arr[k] = L[i];
        i++;
        j++;
        shift++;
    }
    k++;
} 
    /* Copy the remaining elements of L[], if there
   are any */
while (i < n1)
{
    arr[k] = L[i];
    i++;
    k++;
}
/* Copy the remaining elements of R[], if there
   are any */
while (j < n2)
{
    arr[k] = R[j];
    j++;
    k++;
}
return shift;
}
/* l is for left index and r is right index of the
sub-array of arr to be sorted */
void mergeSort(int arr[], int l, int r)
{
if (l < r)
{
    // Same as (l+r)/2, but avoids overflow for
    // large l and h
    int m = l+(r-l)/2;
    // Sort first and second halves
    mergeSort(arr, l, m);
    mergeSort(arr, m+1, r);
    merge(arr, l, m, r);
}
}
/* UTILITY FUNCTIONS */
/* Function to print an array */
void printArray(int A[], int size)
{
int i;
for (i=0; i < size; i++)
    printf("%d ", A[i]);
printf("n");
}
/* Driver program to test above functions */
int main()
{
int arr[] = {4,5,7,2,7,0,1,2,4,7,3,4,7,5,6};
int arr_size = sizeof(arr)/sizeof(arr[0]);
printf("Given array is n");
printArray(arr, arr_size);
mergeSort(arr, 0, arr_size - 1);
printf("nSorted array is n");
printArray(arr, arr_size);
return 0;
}

谢谢!