我应该如何修复此快速排序功能？

Question

Following online resources on the quicksort algorithm, I've reconstructed the following function:

void quickSort(int *array, int arrayLength, int first, int last) {

    int pivot, j, i, temp;
    if (first < last) {
        pivot = first;
        i = first;
        j = last;

        while (i < j) {
            while (array[i] <= array[pivot] && i < last) {
                i++;
            }
            while (array[j] > array[pivot]) {
                j--;
            }
            if (i < j) {
                temp = array[i];
                array[i] = array[j];
                array[j] = temp;
            }
        }

        temp = array[pivot];
        array[pivot] = array[j];
        array[j] = temp;
        quickSort(array, arrayLength, first, j-1);
        quickSort(array, arrayLength, j+1, last);
    }
    printBars(array, arrayLength);
}

To see how it does its magic, I've written a printBars procedure, that prints contents of an array like so

int bars[] = {2, 4, 1, 8, 5, 9, 10, 7, 3, 6};
int barCount = 10;
printBars(bars, barCount);

The final result after i run quickSort on the previously mentioned array bars[] is this graphic

quickSort(bars, barCount, 1, 10);

My questions:

1. Where did 10 go?
2. Why is there a 0 as one of the values (original array didn't have it)?

Answer 1

Array indices are zero-based. So you just want to correct your call

quickSort(bars, barCount, 0, 9);

or preferably

quickSort(bars, barCount, 0, barCount - 1);