quick sort in C

quick_sort.c

// quick sort
void swap(int* a, int* b)
{
    int tmp = *a;
    *a = *b;
    *b = tmp;
}
// 快速排序
void quick_sort(int* arr, int left, int right)
{
    int i = left, j = right;
    int pivot = arr[(left + right) / 2];
    while (i <= j) {
        while (arr[i] < pivot) {
            i++;
        }
        while (arr[j] > pivot) {
            j--;
        }
        if (i <= j) {
            swap(&arr[i], &arr[j]);
            i++;
            j--;
        }
    }
    if (left < j) {
        quick_sort(arr, left, j);
    }
    if (i < right) {
        quick_sort(arr, i, right);
    }
}