```/* QuickSort after tail call elimination and further
optimization */
#include<stdio.h>

// A utility function to swap two elements
void swap(int* a, int* b)
{
int t = *a;
*a = *b;
*b = t;
}

/* This function takes last element as pivot, places
the pivot element at its correct position in sorted
array, and places all smaller (smaller than pivot)
to left of pivot and all greater elements to right
of pivot */
int partition (int arr[], int low, int high)
{
int pivot = arr[high];    // pivot
int i = (low - 1);  // Index of smaller element

for (int j = low; j <= high- 1; j++)
{
// If current element is smaller than or
// equal to pivot
if (arr[j] <= pivot)
{
i++;    // increment index of smaller element
swap(&arr[i], &arr[j]);
}
}
swap(&arr[i + 1], &arr[high]);
return (i + 1);
}

/* The main function that implements QuickSort
arr[] --> Array to be sorted,
low  --> Starting index,
high  --> Ending index */
void quickSort(int arr[], int low, int high)
{
while (low < high)
{
/* pi is partitioning index, arr[p] is now
at right place */
int pi = partition(arr, low, high);

if (pi - low < high - pi)
{
quickSort(arr, low, pi - 1);
low = pi + 1;
}
else
{
quickSort(arr, pi + 1, high);
high = pi - 1;
}
}
}

/* Function to print an array */
void printArray(int arr[], int size)
{
for (int i=0; i < size; i++)
printf("%d ", arr[i]);
printf("\n");
}

// Driver program to test above functions
int main()
{
int arr[] = {10, 7, 8, 9, 1, 5};
int n = sizeof(arr)/sizeof(arr);
quickSort(arr, 0, n-1);
printf("Sorted array: \n");
printArray(arr, n);
return 0;
}
```

### Output:

```Sorted array:
1 5 7 8 9 10
``` 